Monday, June 23, 2008

Basic Architecture of Computer

Like a human structure, computer also has a standard structure which called “Computer Architecture”. As, we human beings have different parts of body to perform our daily activities, Computer too has different devices to perform jobs assign to it. The combination of these devices is called computer architecture. The main and the most important part of the computer Architecture is CPU, stands for Central Processing Unit. It controls all the instructions of computer. Or in simple words, we can define CPU as the brain of computer. The CPU has further two parts, one is called “CU” Control Unit and second is called “ALU” Arithmetic logic unit. The function of CU (Control Unit) is to read and decode instructions and execute these instructions one by one. Where as the ALU (Arithmetic Logic Unit) performs the mathematical operations such as addition, multiplications. The combination of these two is called CUP (Central Processing Unit), which we have already discussed works as the brain of human mind.
The second important part of computer Architecture is its main memory. The main memory used to store the programs. CPU takes the data/instructions from main memory and process/execute upon these instructions and then again sends these instructions back to memory for storage or other purposes required by the users. The main memory also has two basic types one is called “Random Access Memory” (RAM), and the second is called “Read Only Memory” (ROM). Main Memory is the long topic to discuss in detail but here in this post only the main function of memory is enough to mention. (How it works, let this topic for another post). Another important part of the computer architecture is the Input/Output devices. As we have discussed about these Input/Output devices in our early posts. Input devices are used to give the instructions to computer and on the other hand output devices are used to present/display the results. Bus interconnection is also very important part of the computer architecture. These bus interconnections are used to link/connect the different devices (parts of computer Architecture) with each other. Or in other words, these bus interconnections used for the transportation of instructions from one device to other.
So, in the end, we can summarize our post that Computer Architecture is the structure of computer, where we discuss the basic and major devices of computer. First of all, we talked about the CUP (Central Processing Unit) there are two main portions/ parts of CPU, first one CU (Control Unit) performs the de-code of instructions and second part of CPU is ALU (Arithmetic Logical Unit) used to perform mathematical operations. Next we talked about the main memory (also has two types RAM and ROM) used to store programs. Input/Output devices are also used to connect the devices with each other. And these but interconnections are the source of transportation for instructions from one device to other.

Sunday, April 6, 2008

Use of computer in the fields of Education and Medical

When we look around our daily life, we find two very major departments; the medical department and the education department. The computer is playing a very vital role in the both of these departments. As for as the medical field is concerned, computer is serving too much in this field, first we check that what are the activities, which performed in a field of Medical. First of all research; the computer helps too much to research about the virus and treatment. With the help of Internet scientists can share their research work and that research work is available in any part of the word. So, this helped too much and now the treatment is possible for such diseases, which were considered incurable in the past.
Secondly, when we talk about the hospital activities, first of all computer is helping in the administrative departments of the hospital. The help of computer in the administrative department is same as it helps in ay factory or office’s administrative department such as to keep the record of employees, prepare the salaries of staff and keep record of that salaries, furthermore, keep the record of daily visits of patients. So, we can easily know the number of daily visits of patients. In this way, records of patient remains save in the hospital’s database. Furthermore, doctors also maintain the history of patients as well as the history of treatment, which the doctor is providing to his patient. There is also some medical equipment, which is controlled by the computers. These computer controlled equipments observe patient second by second and alerts if find any critical situation so, this was the role of computer in the field of medical.
Now, we discuss the role of computer in the field of education. The history of the computer use in the educational field starts from 1970 when the microcomputer invented. There are two major fields in the education department. One is learning and second is teaching. The use of computer is very helpful in both fields. When we talk about the learning skill, the students can learn from computer as they can learn from any teacher. There are softwares available in the market, which conduct tests, drill and testing skills. There are also some softwares available which help the teachers to explain the concepts in better ways. The use of computer makes it very easy and helpful to teach difficult subjects in easy way.
So, in the end of this post, we can summarize our discussion that computer is helping us in the field of medical and education in the field of medical computer used to perform administrative tasks as well as to keep the record of patient’s disease and the treatment provided to him. And computer is also helpful in the field of medical research.
Computer is also very beneficial in the educational fields. These major educational fields are learning and teaching. In leanings, there are computer softwares, which provide drilling and practice exercises and students can check his knowledge by using testing softwars. On the other hand, when we talk about teaching, with the help of computer it is easy for the teachers to explain the concepts in better ways. Furthermore, tutorial sotwars are also available in the market.


Sunday, March 16, 2008

The Use of Computer in our life

In our previous post we talked about the use of computer in industry. We looked that how computer helps us in office or factory environment. Today we will see that how computer is helpful in our other matters. It has become that part of history when the mail delivery took too much time to reach to reach its destination. Now, with the help of computer our message reaches to its destination just within a second. This type of mail is called Electronic Mail or E-Mail; we can send E-Mail in any type of data. Such as text, image, audio and video. If we want to send simply text message, we will just type our message and then send it, but if we want to send other data type file, we will use the attachment facility. We can attach the other file with our mail and that file/files also delivered to the desired E-mail address. So, in short, we can say that the use of computer in the field of mail brought a very positive change and now the mail delivery time has been reduced from days to seconds.
It was also a long process to arrange the meetings. First of all, inform the members about the meeting place and time, then the participants will prepare on their end. They have to travel long distances, some had to travel from one city to another. But the use of computer has made it too much easy to arrange meetings or in other words, we can say that the traditional meetings have been replaced with the videoconferences. All the participants take part from their offices or from their homes. They just need a computer and Internet connection. So, all members can share their ideas and views along with their live videos.
Another major advantage of computer use in our life is it, that it brought a revolutionary change in the field of Banking, this called E-Banking. With the help of E-Banking, our accounts and all other bank related activities remain under our access or observation twenty-four hours. We can check our bank balance with ATM and we can also withdraw amount any time. We can check our balance through computer and Internet and even from our cell phone. So, E-Banking is also due to the use of computer in the field of banking.
The use of computer has also made our sale and purchase very easy. Now, where it is easy for the manufactures to sale their products, it also very useful for the customers to purchase. Now, the customers can purchase anything and anytime from their home. We need just a computer and Internet connection. We will visit to products web site and then we can place our online order.
So, in the end we can summarize our post “ The use of computer in our life” in the following words that the use of computer has totally changed our life. We find computer in almost all the major departments of our life. In our previous post we discussed how computer is helping us in offices and factories. In this post we talked about E-Mail, E-Conference, E-Banking and E-Shopping. E-mail is the replacement of our traditional mail system and now we can send mail along with other file attachments just in seconds, where as in past, it was a long and time taking activity. E-Conference is the replacement of traditional meeting system and now the participants can participate from their offices or even from their homes. And same way E-Banking made it possible that we can use all the banking services from our homes and due to the E-Shopping we can purchase anything anytime from our home and on the other hand, E-Shopping is helpful for manufactures to sale their products.


Saturday, March 1, 2008

The Role Of Computer In Business

Almost two hundred years ago, nobody was familiar with the word of computer and it was unbelievable at that time that one day computer will become the essential part of our daily life.
Today the use of computer has become compulsory in the all fields of our life. Here we will discuss the use of computer in our daily business life. Once there was a time when offices were full of registers and files and factories and offices have large record rooms full of register and manual workings. And it was a hard activity t find about anything. But now, the computer has made it too much easier to manage our data. We manage the records of our employees, all personal information of employees. Furthermore, we store and manage the daily attendance of employees, their “Time-In” and “Time-Out”, in short, we generate our payroll with the help of computer and store all the employees’ personal records and it is too much easier to locate any specific record.
There is also accounting software available in the market, which, help us to manage our accounts activities, such as to calculate the taxes to generate the profit and loss reports, vouchers of all expenditures.
Computers also help us to manage our inventory and like accounts software, inventory softwares are also easily available about in the market and the stock remains always in front of our eyes. It helps us to take decision that what items are urgently required and where the items are over loaded. In short, our store stock and warehouse position always remains under our observation due to the computer.
Where computers help us to manage our accounts and inventory it is also very useful as for as the sale is concerned. If a factory has more than one outlet (shop) in one or different cities. We can update our daily sales with the help of computers. We can replicate the data from sales point and in this way our main database updates. The sales man puts the amount of all items and this one time activity prevents him to calculate again and again the list of sold items. Customers also receive the detailed printed receipt of items with the individual price items quantity, total amount and the grand total. Computer also calculates the taxes and all is easily possible due to the use of computer.
So, in the end, we can summarize our post that computer is very vital invention of last century. Prior, the invention of computer it was too much difficult task to manage our data but with the help of computer, it has become too much easy to manage our day-to-day activities in all fields of life. In this post, we discussed the use of computer in our business. We can save the adman’s related records such as the information of employees leave record; we generate the monthly payrolls and all the records related to payrolls such as salaries, salaries taxes and benefits.
Computer is also very useful in the accounts department and helps us to manage account records, it helps us to calculate profit and loss reports and generate accounts ledgers. Computers help us to maintain our inventory system, to maintain our store and warehouse stock positions and in the end we discussed how computers help us as for as the sale is concerned. In our future posts we will look that how it is useful in the other fields of life.


Friday, February 22, 2008

The Communication Medium

Before writing about the communication media, I would like to explain some terms or definitions related to data communications. When we talk about he data transmission, there are two types of transmissions. One is called serial transmission and second is called parallel transmission. As shown by the name, in serial transmission data transmitted on bit by bit. At a time only one bit will transmit whereas on the other hand when we talk about the parallel transmission data transmitted in sets of 8, 16 or 32 bits at a time. So, the parallel transmission is much faster as compare to the serial transmission but we use this parallel transmission only for short distances but when we want to transmit data long distance then the serial transmission is recommended.
Now, we come to our post title “the Communication Media” media is a source which, we use to transfer data from one place to another or in other words we can say that when we transfer data from one place to another place, we must use some sources to transfer data from one place to another place, we must use some sources to transfer it, these sources are called the “Communication Media”, Furthermore, these media has further two categories, Guided Media and the Unguided Media. When we use some physical media for our communication such as cables that is called guided media. On the other hand when our data transfers through some non-physical resource, this is called unguided media. The unguided media only used as a medium for data traveling, and not guide the signals towards any specific path that’s why this called unguided media. Microwave transmission and the satellite communication are its examples. When we talk about the microwave transmission, it is high-speed data transmission media but in this media we have to face little problem that signals travel only in straight lines so, we have to use microwaves antennas on a very high place to avoid the earth curvature. The 30 miles height for microwave antennas is recommended. These antennas receive signals from the previous antenna and then transmit it to the next antenna. Satellite communication is another form of unguided media. In these media two things involves. First, earth station and second satellite station. The earth station throws the signals to the satellite station, which is almost 23,000 miles to 24,000 miles above the earth that satellite station boosts up the signals and then transmit them to another earth station. So, these were the examples of unguided communication media. Now we will talk about the guided media
When the signals use some physical media for communication or when the signals travel through some physical media, this is called Guided Media. The following are the examples of Guided Media.
Coaxial Cable
Coaxial Cables are recommended within the range of one Kilometer or for the local area network. It is a copper wire that surrounded by the insolating material
Twisted Pair
These are the Cables of thin diameter, in the form of twisted pairs but it is not as reliable as the Coaxial Cable
Fiber Optic Cable
This is the fastest medium and it consists of hundred of thin glass. It also provides the high security level but it has also a disadvantage that it cannot support for the long distances.

Sunday, February 10, 2008

Modes of Data Communication

When we talk about the data communications. It involves the communication of data between two devices, mostly between the computers and sometimes other devices like cell phones, radio and T.V etc. the data travels in some particular direction or in other words, I can explain that when any data communication activity performed, there involves sending devices and receiving devices and the data, which, is being communicated, travels from sender to receiver. So, the direction in which the data travels is called “Data Communication Mode”. This data communication mode has following types.
Simplex Mode
In simplex mode type, the data travels in only one direction and there is no possibility to change the direction of data. In other words, we can say that the direction of data will always be same between the two communicating devices. The device which is receiving the data (Receiver) cannot send the data in reply, were as on the other hand the sender will always send the data and cannot receive the data in reply. So, we can say that in simplex mode of data, the data always travels in only one direction and that direction is from sender to receiver.
Half-Duplex Mode
The second type of data communication mode is “Half-Duplex Mode”. In this type the direction of data could be towards the both sides. I mean to say that data travels from sender to receiver and the receiver, in response can also send the data to sender. We can understand this Half-Duplex Mode further by the example of a server and client communication. We have a database on server and on the other hand we have a client computer. Now from the client side we send a query to server where we ask for all the records employs having the grade three. So, when we write the query on the client computer and send it to the server, the direction of data is from client to server, in response of this query, server sends all the records (data according to query) to client computer. Now, the direction of data is from server to client. So, the data direction of data is in both directions, first from client to server, then from server to client. The further important point of Half-duplex Mode is it, that though, the data ravels in both directions but at a time data can travel in only one direction, when the activity is completed in one direction, then second activity will start in other direction. In short, we can say that data cannot travel in both directions simultaneously. Though, the direction of data could be change. Half-Duplex mode is better than the Simplex Mode, but it is not a quick communication mode because the device will have to wait to change the direction until the communication in one direction is completed.
Full-Duplex Mode
The third and the speediest type of data communication mode is the Full-Duplex Mode. In this type data can be travel in both directions at a time. The sender can be receiver as at a time and the two devices send and receive data simultaneously. So, the Full-Duplex mode is the faster mode as for as the data communication modes are concerned.


Tuesday, February 5, 2008

Analog and Digital Signals

There are two types of signals one is called analog signals and the second type of signals is called digital signals. Analog signals are the continuous form of the wave. Whereas, the digital signals have only two possible values, the maximum value of he signals/waves or the minimum value of the signals/wave. Furthermore, we can define or understand the two types of signals in this way that the analog signals the value of the signals is always on changing form and the value of the signals is called amplitude. If we talk about the amplitude, the waves travel in the horizontal axes. While traveling on the horizontal axes the maximum value is called the maximum amplitude same way the minimum value, while traveling on horizontal axes, is called the minimum amplitude. When the signals reach at its maximum amplitude next the decline of the signals starts and the value continuously decreases until it reaches to its minimum amplitude. After that again the value of signals start to increase and increases until again it reaches to its maximum amplitude. This process from the maximum amplitude to the minimum amplitude and then again to the maximum amplitude is called a ‘Cycle’. These cycles complete in so swiftly and the number of these cycles completed in one second is called the frequency.
Whereas on the other hand, if we talk about the second type of signals, that are called the digital signals, we can only find the maximum value or the minimum value and there is no value between these two values because in digital signals the change happens suddenly, not gradually and continuously as it happens in analog form.
Now, when we talk about the data communications of computer networking, we come to know that these types, analog and digital are closely concerned with each other. As we have already discussed in our previous post “Data communication and its elements” that all the communication within the computer happens in digital type or in other words, computer only understands the digital signals where as telephone lines required as source of communication in WAN (Wide Area Network) and the telephone lines only support analog signals, so, the conversion is required from digital to analog and from analog to digital. And for the conversion purposes, we need encoder and decoder. Modem is the example of encode and decoder devices. Modem takes the digital signals form computer, converts it into analog form and these analog signals travel through the telephone lines and on the other end, again modem takes the analog signals and convert them in digital form, so, that computer can understand these signals.
So, in the end we can summarize our post in the following words that there are two types of signals, one is called analog signals and second is called digital signals. In analog signals travel horizontally and the value of any place is called amplitude, the process of maximum amplitude to minimum and from minimum to maximum is called a cycle.
Computers only understand the digital signals and telephone lines only support analog signals. So, encoders and decoders used for conversion purposes.


Saturday, February 2, 2008

Data Communication And Its Elements

When we transfer data/information from one place to another this process of transferring data/information is called “Data Communication”. Now there are different ways and mediums to perform the data communications, and it depends on the distance between the locations of devices/computers. The following elements involve performing a data communication. Lets know about these elements.
First of all, there is information or data, which, we want to transfer from one place to another. We have discussed in our very first post about the data and data types. Again for reminder, the data/information may be in four forms, text, image, audio, video or the combination of these types. So, the data or information that, we want to transfer is called message.
Now, the next step is the source which, we use to send that data. I means to say that I have selected the data/information to communicate but to transfer it we need some device. This device is called transmitter or sender. Computers are mostly used as transmitter/senders. So, we have selected the message and sender/transmitter now we need the source or medium which, the sender will use to send the data/information if there is little distance between the communicating devices (sender and receiver) we can connect these devices with the wire but if there is long distance between the sender and receiver. Then the source of data traveling may be telephone line, microwaves or a fiber optics. In short, the medium is required for data communication and this medium may be fiber optic, telephone line or the microwaves.
Now, before I write about the next element involves in data communication, there is need to explain little but about the analog and digital signals. As we know that all the computer’s internal communication is based on digital signals. Because computer knows only binary language 0 and 1, and this binary language is digital language. The computers only understand and communicate in binary (digital) language. But if our medium is such channel which, and not support digital signals and only work with analog signals, then we need encoder and decoder. The only function of encoder and decoder is to convert analog signals into digital signals and digital signals into analog signals. We explain this encoder and decoder with the example of modem. I think everybody who uses the Internet services from his/her computer is familiar with the device called modem. This modem is encoder and decoder device. When we connect to the Internet our data communication starts at once. This communication performed through the telephone line the modem’s function is to convert the incoming data (which is in analog form) into digital formant as well the outgoing data (which is in digital form) into analog form. So, we can say that the devices, which convert analog into digital and digital into analog, are called encoder and decoder devices.
So, the next element involves in data communication is receiver as we have sender to send the data/information, same way we have receiver to receive that data/information on the other end.
In short, if we take a look over the “Data communications and its elements”. We can summarize it in the way, that when we transfer some data/information, in its any form, the process of transferring is called “Data Communication” and the message (data/information) is the material we want to transfer or receive, sender is the device to send the message, Medium is the source to send the message. This medium could be fiber optics, telephone line or micro ways. Further, there involves decoder or encoder to convert the data/information into digital to analog as well analog to digital form and finally receiver receives the data/information.


Wednesday, January 30, 2008

Networking Topologies

There are more than one ways to connect the computers with each other. The way in which, we used to connect our computer is called “Topology”. Or in other words, the “Physical layout for a network” is called network topology. Here we will discuss most common topologies one by one.
Bus Topology
In bus topology we use wire as a backbone. The recommended backbone wire is thick-wire with 4” dia. So, this wire is the medium of communication and the other terminals are connected to this wire (backbone) with thin-wires the both corners of backbone wire are closed with device called terminator. These terminators are designed to absorb the signals from the both ends. Now one of the terminals attached to the network sends data along with the particular address of the desired terminal. This data goes to all the terminals but only that terminal receives the data which’s address is attached along with the data. So, at a time, only one communication could be performed so, due to this reason bus topology is little bit slow but it is recommended where the number of terminals are small.
Ring Topology
The Ring Topology is another way to establish a network. In this topology every computer is connected to the next computer and the last computer is connected to the first computer, in this way the ring of the computers complete. Now the one of the computer pass the data/information to the next computer. The next computer receives that data if the next computer is the destination of data, it means the communication completed, but if the next computer is not the destination of data, that computer will pass the information or data to the next computer and this process (receiving the data, check it and pass it to the next computer) will continue until the destination computer receives the data. The next activity will be start when the previous one is completed successfully. The major disadvantage in this type of topology is it that if one of the computer or nodes is out of order, the entire network will also falls down. Furthermore, the troubleshooting and adding or removing the computer is also difficult task
Star Topology
In Star Topology all computer connected a device called “Hub”. The computer send information/data to the Hub and then hub transfers that data to its destination. As for as the advantages of this topology are concerned, first of all it is easy to setup and maintain. We can detect the troubleshooting easily as compare to the previously discussed topologies. And the failure of one computer will not be the cause of entire network failure. It is also easy to adding or removing computers in the network. Simply, we can attach the more computers to the hub as well as remove the computer for it. But on the other hand, this topology is costly as compare to the previously described. First of all, we need a costly hub then the more cables are required in this topology.
Tree Topology
The Tree Topology is the combination of two (Previously discussed) topologies, Bus Topology and the Star Topology. Firs, we configure different star topologies and then we connect these star configured topologies to a backbone wire. In simple, words, we can explain that same like bus topology we connect group of computer (connected with each others using star topology) where as in simple bus topology, we connect single computer to the backbone wire. If we talk about the advantages of this tree topology, its main advantage is it that it can support a large numbers of computers. But on the other hand, it is very difficult to setup and configure and the fault in the main wire (Backbone) will shut down the entire network.
Mesh Topology
In Mesh topology ever computer is directly connected to the other computers on the network. So, it is easy to communicate with one and other computers. Furthermore, there are more options (ways) available for the data/information to reach on its destination. So, its fast in speed and the fault in one computer does not effect on the entire network. But it is difficult to setup and configure if the number of nodes is large.
So, these were the main and commonly used networking topologies.

Networking Models

In our previous posts we have talked about the “Networking”. Here we will learn about the Network Models. There are two main Network Models, these Network models also known as Network Architectures. These Network models/architectures are Client/Server and Peer-to-Peer.
First we talk about the Client/Server model and see what are the advantages and disadvantages of this model. In client/server model, there are two types involves one is the client and other server. Mostly, we find and server with high processing speed. On the other end, we find clients computers, connected to the server. So, the server’s min task is to provide the services to its client computers. When they request, the server also manages the resources available on the networks. Such as hardware resources software resources and it also provides the large storage for the clients connected to it. So, we can say the client computers are depending on the server to utilize the resources of a network. If we talk about a large network, working on this mode, Client/Server we will find more than more than one server and too many clients connected to these servers. Here the servers performs and manage specific tasks assigns to them, for example one server will manage the printers and printing requests, the other will manage the software installed on it and third will manage the storage resources So, these types of severs are called “Dedicated Servers”, means dedicated to one or more than one jobs. But mostly, in a small office networks we find one server with heavy resources and the clients connected to the server.
Now, lets see some advantages and disadvantages of Client/Server Model.
First of all in a Client/Server model we can handle a large number of users and if the users increase, we can increase the servers too and assign the specific tasks to these servers.
This model also provides the high security level and can restrict the users access. For example, it can give the permission to add or edit the data and programs and it can give the permission just to read – only data.
Here in Client/Server model we use only one expensive server and the clients may be low cost. Because all the major activities performed on the sever side, so, the low resources clients can used for the users.
In offices and large organizations, many users work on a single database. So, we install that database on the server and all the users can use that data simultaneously. And when the data is stored on a single place, its easy to maintain the backups for that data
There are some disadvantages of Client/Server model. In this model we need a costly server with high resources. And in addition we need to hire a network administrator to manage the server and networking. If the server is out of order the all the network will shut down because the entire client computer are depend on the server.
The second networking model is called “Peer-to-peer” model. The major difference between the Client/Server model and Peer-to-peer model is it, that in peer to peer model there is no any server but all the computer get and provide the services to other computers.
In Peer-to-Peer Network we connect the peripheral devices (additional devices such as printers and Scanners) with any computer and other can use these peripheral devices peer-to-peer network model is recommended where the number of computers are between 2 to 12.
In this model we don’t need to manage an expensive server and network administrator, because its setup is simple and easy.
But it is not recommended where the number of users is large due to the following reasons/disadvantages.
First of all, it cannot perform fast speed because the resources of computer are shared and used by more than one user; so, it reduces the speed of entire network
Peer to peer model cannot supper the security management. So, the data is not secured as it is on Client/Server model. Its also difficult to arrange the backups from different computers because data is not present at a single place as we find the Client/Server model.
So, in the end we can conclude that in small offices where we have users between two to twelve, peer-to-peer network model is recommended and in the organizations where we have large number of users, Client/Server model is suitable

Monday, January 28, 2008

Internet And Its History

In our previous topic, we have talked about the networking, now here we will discuss that what is Internet? And what is the history of Internet. We can simply say that Internet is the network of millions networking around the world. Or in other words, the millions of computer from all over the world are connected with each other to share the data in its all forms. Such as text, images, audio and video. These networks use telephone lines, Fiber – optic cables and satellite communications for communicate with each others. And to utilize these major forms of media, there is the need of both hardware and software. So, as for as the use of Internet increased, the globalization of the World became towards the reality.
If we have a glance over the history of Internet, we will come to know, that US department of defense designed a network called ARPANT (Advanced Research Project Agency Network) in 1960. And its purpose was to share the researches and work of Scientist from the different locations. So, with the help of this (ARPANT) it seems as they were sitting and working together. So, it was the first step towards the modern ways of sharing information.
The other networks related to the military points of view came into existence with the passage of time and the period of between 1970 and 1980 was very important period as for as the history of Internet concerned. Because in this period (1970 – 1980) mostly military related networks emerged into ARPANT. On the other end, networking was gaining the popularity and almost all the major Universities and Research Centers also joined the ARPANT. And now, we can say that ARPANT become the “Network of Networks”.
A major point was taken place in 1989, when ARPANT was replaced with National Science Foundation’s Network (NSFNET). Prior to this the Internet was serving the Scientists, Teachers, University students and Military Officers. In short, the users of Internet were limited but in 1989, when the NSFNET came into existence all the civilians communities started to get benefits of Internet. With this, as the number of Internet users grow and the popularity of Internet also grown. The period of 1990 to 2000 was the period when the rapidly growth and the popularity of Internet was on its peck. After the 2000, the period of modern Internet was starting. Prior to 2000, Internet was being used for the informational purposes, mostly the users join it when they need information or to communication purpose such as E-Mail or Chatting. But after 2000, Internet became the source entertainment too. Now, where it provides information and communications, it also provides the entertainments.

Wednesday, January 23, 2008

Networking And Its Benefits

When we connect two or more than two computers with each other it called “Net Working”.
Now the question arises why we need networking? Infect, networking has lot of plus points and has advantages over the single PC. First of all, networking increases the productivity of entire network. For example, we are working n a file and now we want to present that file to our manager or boss. So, what e will do? First of all we will arrange some floppy disk or pen drive then we will write it on that floppy or pen drive, again we will convert it to the required computer. So, this activity involves more than three steps. But if we want to do it in a networking environment we will just copy the file on the desired computer drive, which, will be shared on the network. So, it reduces the time and increases the productivity.
Then next advantage of networking is cost saving benefit. Networking is a less expensive thing as computer to the other exercise to perform the same activity. We don’t need the floppy drives, we don’t need to pen drive, we don’t need the individual printer and scanner, means to say that in a small office environment where we have only tem computers. We can use only one printer and can print from any computer. In networking environment, we also save the disk space. We only share a main hard disk (Server’s hard disk) and install main programs on that server hard disk and then there is no need to install the software an individual computer. In networking environment its easy to maintain the computers if we don’t have networking we need to pay consultation on individual computers but in networking, environment, we need only one computer expert called network administrator. He can easily manage all the connected computers. He pays special attention to server (because all the important data and programs are saved on the shared server and he can also restrict the users to that the users can’t harm the computers. Other great advantage of networking is the sharing of devices. As we have talked about it already, that without networking we need individual printers for individual computers. But in networking environment, we only attach the devices with server, or another computer, which, is the part of network. And all the users can utilize that resources (devices). Same way, we place the software and the data store on the server and all the users use that software and data from that server. In a network, everybody can communicate with the other members of network. They can chat, they can discuss about the serious matters just sitting on his/her seat and all is possible in a networking environment. Networking also provides lot of securities because all the important data and all the software are installed on the server and network administrator can easily manage the security of that important data. But imagine, without networking network administrator has to take back ups from individual computers.

Saturday, January 19, 2008

Computer Software

There are two types of computer software.
1) System Software
2) Application Software

System Software is the software, which, are compulsory to run the computer, or in other words there are the software required by the computer hardware. These software manage the computer resources. Main example of these software are operation systems and drivers. Just take the example of operating system. Operating system works like bridge between hardware and application software. Without system software, we cannot use application software.
Application Software helps us to manage/perform our tasks according to our requirements. Or in other words, we develop these software according to our requirements. i.e. to manage our accounts or to maintain the inventory system. Every body cannot develop these software. So, there are software houses where the professionals programmers and developers develop the software according to our requirements. the person who uses these software is called the user and who develop the system software is called developer or programmer. Developing a program or system is not an easy task but we can do it with a proper managed way. This way or steps to develop any system is called “System Development Life Cycle. At the very first state we identify the requirements. This is the very important stage because all the future steps depend on this initial step. Then we find out more than one solution to develop the system so we can select the best amount the all other possible ways. In this stage we get more and more information about the system, which, we are going to develop. And we arrange some meetings with clients and the users of the system so, that we can get collect more and more information. After this stage we write a report (called feasibility report) in which, we describe all the possible solutions and then also mention the best solution. Then we forward this report to the project manager for approval so, project manager passes this report and amend where it necessary. Then the programmer winds up the information and requirement then the programmer observes the previous system, it may be in the shape of manual reports or may be the system, which, user wants to upgrade. Next stage is the logical design stage. In this stage developer logically develop the system and after it convert logical design to physical system construction. After it programmer writes the coding of the system so, that if some other programmer want to amend the programs. Next the testing and the implementation of the system comes. Some time they direct implement the system but the parallel implementation is recommended. Parallel implementation means that don’t stop the previous running system in the company and start new developed system and after some time, when the user/client satisfied with the system then stop the previous system. And in the end maintenance and up gradation of the system is required time to time

Output Devices

There are two types of output devices. One is called Soft copy outputs and the second is Hard copy outputs.
Soft Copy Outputs
System reports and the Preview reports are Called Softcopy Output reports. The main output device of this category is Monitors and Screens. These monitors and screens are different from each other by the colors, size, resolution and graphic cards or display adapters. The 256 colors combinations are used in these monitors. The most commonly used size for monitors is 15” or 14” and unto the large sizes of monitors.
Cathode-Ray-Tubes are the most common monitor type. In this technique, bits converted to the electrons by the electron gun. When this electrons stick on the phosphor coated surface, it creates images on the monitor screen. This technique is also used in TV sets.
FPD (Flat Panel Displayer)
These types of monitor are lightweight but expensive as compare to the CRT (Cathode Ray Tube) monitors. But this type is suitable for the portable computers. The most common of this type are LCD (Liquid Crystal Displayers). In this technique, there are two glass plates and between these plates, there is a liquid crystal stuffed. This liquid crystal stuffed layer between the two glass plates creates the image. So, these are the most common soft copy output devices now we talk about he hard copy outputs. Printers there are also two types of printers. First type is Impact Printers and the second is Non-Impact printers.
Impact Printers
Impact printers works just like the typewriters. There is ribbon between the hammers like characters and when these characters struck like hammer on the inked ribbon, it prints the character on the plane paper. Or in other words, there is an ink ribbon between a plane paper and characters. And when character struck on the ribbon, it leaves the image on the paper. These types of the printers are slow in printing but this printing is not as expensive as compare to the other printers type (non-impact printers). So, impact printers are used where the heave printing is required. Though, print slowly, but the cost per page is too much low as compare to other printers. The quality of this printing is also not too good; I mean it gives poor printing quality. But yet have its own benefits.
Non – Impact Printers
Non – Impact Printers work like the photocopier machine. It gives the speedy printing and the qualities of these printers are too much good as compare to the impact printing quality. But this type of printing is costly. These printers are not recommended where the heavy printing is required.
Speakers
Speakers are also one of the types of output devices. It used to out put the audio formatted files. There are lot speakers types are available in the market. So, these are the most commonly used output devices.

Friday, January 18, 2008

Input Devices

When we talk about the computer, we must talk about the data, data processing and information. And to enter data in computer for processing and results first, we need some devices. So, all the devices used to enter the data (in any form) are called input devices. First it is compulsory to describe that there are four forms of data. These types are Text, Image, Audio and Video. Now, we have different devices to enter these four types of data. Here we discuss most commonly used these input devices.
Key Boards

The most commonly used input device is “Key Board”. The Key Board is used to mostly enter text data type. The first line of buttons on Key Boards (in most key boards) is function buttons key. These function keys are from F1 to Pause/Break key button. These function keys are shortcut keys to execute different commands according to the software and operating systems. For example in most applications F1 key is used to get some help and F2 key is used to execute the exe etc. on the top left corner we find the escape key, mostly used to skip some commands or to have escape from previous screen.
Then there on the Key Board, we find a Tab Key. This tab key used to set stops on the paper. Caps Lock key used to turn on and off the Upper and Lower case of alphabet character (A – Z). If it turned to on, the character will be typed in the upper case and when it pressed to off (if the light under the Caps Lock button is turned on it means its turned to on and if that light is off it means that caps lock is turned off) the characters will be typed in lower case. Shift Key works with the combination with other keys available on the keyboard. If we press any character + shift key the character will be typed in the upper case. Ctrl Key also works with the combination of other keys. This key is mostly used to run commands according to the software commands. Alt Key also works with the combination of other keys. This key is mostly used to run commands according to the software commands. Back Space and Del Keys used to erases one character. Different in both keys is only it that the Del Key erases one right character from cursor where as the Back Space key erases one character from the left side of current cursor position. Enter Key is used to execute the programs and also used to start typing from anew line. End Key used to move the cursor at the end of current line where as Home Key move the cursor at the start of current line. Arrow Keys there are four arrow keys on the Keyboards. Right arrow, Left arrow, up arrow and the Down Arrow. Right arrow move the cursor one space right to the current position of the cursor, Left arrow moves the cursor towards the one left character. Up arrow moves the cursor to up line and down arrow moves the cursor towards next down line. Page Up and Page Down as the p arrow key moves cursor to next up line, page up move the cursor to the next page up and page down moves the cursor to the next down page. Ins key, when pushed on, it over-writes the per-existing characters. Print Screen used to print/the current screen in image form and the Scroll Key is used to scrolled all text and images appears on the screen but not let the cursor to scroll. Pause Key used to pause the swiftly moving information. For example, if we type dir in the Dos. Mode computer will show the list of directories and files too fast that we can’t read this information. So, we can pause this information until we read it. And there are also alphabets from A to Z, numeric keys from 0 to 9 and finally the mathematical operators keys such as +, -, *, etc.
Now, the multimedia Keyboards are also available in the market. In these multimedia Keyboards we have play/pause/still/stop/forward/rewind/volume up. Volume down function keys is available for audio and video format files. The next type of input devices is Pointing Devices.
Mouse is the most common example of pointing devices. It looks like a mouse and it moves the cursor as we move it. In which direction we will move mouse, the cursor will also move towards that direction. There are also two click points available on the mouse. One is called right click and the other is called the left click. When we want to open/execute any icon, we position the cursor to that icon with the movement of mouse and then we will click the button to complete the task. We can also select the text and images with mouse. In some mouse, we find a scrolling wheel in the middle of right and left clicking points. Scrolling this wheel we can scroll the screen to up and down.
Track Ball mostly used on the laptops. It is just like a moveable ball and we move the cursor with the movement of this track ball.
Pointing Stick looks like a pencil eraser, placed between the G, H and B keys. It also used to move the cursor to our desired position s we move it with our fingers.
Joy Stick is used to control the video games or in other words joystick is a video game controller.
Touch Screen mostly used with laptops as we move our finger over the touch screen the cursor also move towards that directions.
Light Pen is just like a pen connected with computer with a wire (wireless light pens are also available) as we position it to our desired position; we press a button on it to perform our desired task.
Pen Based System with the help of this device we are able to directly put data in our handwriting as we write, our writing stores in computer.

There is another family of input devices which is called the “Direct Input Devices” using these devices we can very fast input our data with less struggle. Most commonly input devices are Scanners, Digital Cameras and Microphone. Scanners scan the data and directly store it in the computer we can scan and images papers etc. Scanners converts that papers into digital computer acceptable form and then store it in computer for future use or further process. Other direct input device is Microphone used to store audio data type. It input the all sound/audio data type into computer. And finally we have Digital Cameras, which, we use to input images and video type o data to out computers. We can input our still images as well as our video data types.
So, these are the most commonly used input devices

Main Functions of Computer

The word ‘Computer” is abstracted from the word “Compute” which, means calculate. But if we restrict computer definition that computer is a device, which, helps us in solving our mathematical problems, it would be injustice with the computer. Though, there is no doubt that computer helps us to solve our mathematical problems but to solving and helping in our mathematical problems is just one of the works, performed by computer. So, we can say that computer is device, which can help us in:
Programming, Processing and storing the data we can develop programs according to our requirements and needs. We can process our data on computer to make it information and computer stores data, which is also very important role. All these functions of computer are very important and play very vital role to create “Global Village”. It takes the data for processing then process it, stores it and shows/provides information. These mentioned tasks of computer are called “Input”, when we enter some data in computer it called “Input” after inputting the data, next step is process (we can store the unprocessed data too) then it process the data. It called “Processing” and next it gives results after processing, which called “Output”. And finally, computer stores the data for future use.
There are two major parts of computer.
1) Hardware
2) Software

So, we can say that computer is the combination of hardware and software and it takes inputs give results after processing and stores data for future use

Global Village and the role of Computer

Today the world is called as “Global Village” and it is possible due to the rapidly growth of sharing information. Now, the question arise that what is the “Sharing Information”. First, Let me define what is information. To know about the information it is compulsory to have some knowledge about the data and data processing. Data is a collection of raw material about any particular thing or person or in other words unprocessed or unorganized information is called data. When we have collected the data our next step is to arrange it so that I become some useful information. To do so, we need some processing on it (our collected data) and when we process the data, it becomes useful information. So the sharing of this information leads us towards the globalization of world. In the present era, every passing moment has a story in itself. Every second gives us lot of to know and the events from all over the world are ready to share them. So, the circle completes in this way:
1) First, Collection of row figures and facts about the rapidly changing events
2) Process on these collections of data so it becomes some useful information.
3) Share this useful processed data (Information)
All these above mentioned steps leads us towards the “Globalization of World” it was not possible prior the invention of computer. But as the computer become a common device in all over world. The information (in any sort or form) compiled and ready for share so, if the current world is called “Global Village”. It is only due to the computer because it helps us in above-mentioned three steps, which, leads us towards the “Global Village”. For example, it helps us to collect the figures and facts (Data). Then we can process data according to our requirement so, that our data become some useful information and finally it plays a very vital role to share that information. So, it would be rightly to said that “Globalization” is just due to the device called ‘Computer”