The computer is an electronic device that is used to solve various problems according to a set of instructions given to it.
The term computer literacy refers to the knowledge and understanding of computer and its uses. A person is computer literate if he understands computer and its applications.
A collection of raw facts and figures is called data. Data is collected from different sources. Data may consist of numbers, characters, symbols or pictures etc.
During census, governments collect the data of all citizens of country. Government stores this data permanently to use it for different purposes at different times.
The processed data is called information. Information is an organized and processed form of data. It is more meaningful than data and is used for making decisions.
In colleges and universities, raw facts about students are stored on admission forms. If we want to find out a list of all students who live in Faisalabad, we will apply some processing on data. The processing will give the desired list. This list is a form of processed data and will be called information.
Data processing life cycle is a collection of steps required to convert data into information. The steps of data processing life cycle are input, process, output and storage.
The major components of a computer are: storage devices, input devices, processor (CPU), output devices, and memory. Storage devices are used to store data, instructions and information permanently. The CPU uses memory to temporarily store programs and data for fast access. Input devices are used to accept input from the outside world. Output devices send information to the outside world. The processor (CPU) processes data based on the software or firmware instructions.
A hardware component used to enter data and instruction into computer is called input device. Common input devices are keyboard, mouse, microphone, scanner, digital camera and PC camera.
A hardware component used to display information to the user is called output device. Most commonly used output devices are monitor, printer and speaker.
System unit, also called chassis, is a box that contains different electronic components of computer system. It protects the internal components from damage. Electronic circuits in system unit are connected to motherboard.
Two main components of system unit are Central Processing Unit and Memory. CPU is also called processor. It interprets and executes the instructions in the computer. The hardware component that stores data and instructions temporarily is called memory.
The hardware components used to store data, instructions and information permanently are called storage devices. Some important storage devices are floppy disk drive, Zip drive, hard disk drive, flash drive, CD-ROM drive, CD-RW drive, DVD-ROM drive etc.
A USB flash drive is portable and has much greater storage capacity than a floppy disk or Zip disk. Its weight is light enough to be transported on a keychain or in a pocket.
A person who develops application or system software. Programmer writes instructions to direct computer to process data into information.
Following are the important characteristics of a computer:
Storing – It can store data and information permanently.
Processing – It can process the given instructions.
Recalling – it can recall the stored data and information as required.
Control Sequence – It executes instructions by following the same sequence given in
. the program.
The hardware components used to communicate and exchange data, instructions and information with other computers are called communication devices. An important communication device is called modem.
The two most popular series of personal computers are PC and its compatible computers use Windows operating systems, Apple Macintosh and its compatible computers use Macintosh operating system also called Mac OS.
Personal computer is a type of computer that performs input, output, processing and storage activities by itself. It consists of input device, output device, storage device, memory and processor. Most commonly used personal computers are PC and Apple Macintosh.
The computers that follow the specifications of the original IBM personal computer are called PC compatible computers. Some PC compatible computers include Gateway, Compag, Dell and Toshiba.
Desktop computers are the most common type of personal computer. It is designed in a way that all its components fit on a desk or table.
All-in-One computer is a less expensive computer. In this computer, monitor and system unit are combined into single device.
Different types of personal computers are desktop computers, notebook computers & Tablet PC.
Workstation computer is more expensive and powerful computer. It is used for calculations and graphics work and are used mostly by engineers, graphics artists and architects.
Notebook computer is also called laptop computer. Laptop computers are very small in size and can be placed easily on lap. They can be used using batteries. Laptop computers are more expensive than desktop computers. In notebook computer, keyboard is placed on the top of system unit.
Stand-alone computer is a computer that performs input, output, storage and processing activities by itself without being connected to other computers. However, many stand-alone computers also have networking capabilities.
Server computer is a computer that manages the resources of a network. It controls access to the software, hardware of network and provides centralized area to store data, information and software.
Handheld computer is also known as palmtop computer. It easily fits in the hand of the user. It contains small screen and small keyboard. Some handheld computer have no keyboard at all. Handheld computers usually have no disk drive. The programs and data are stored on chips in the system unit.
PDA stands for Personal Digital Assistant. It is used to organize personal information. It provides the facilities of calendar, appointment book, address book, calculator and notepad. Some PDAs provide word processing and spreadsheet functions.
Tablet PC Resembles a letter-sized slate. It allows you to write on the screen using a digital pen. It is Especially useful for taking notes.
Web-Enabled Cellular Telephone is also called smart phone. It is used to send and receive messages on the Internet. It can also browse websites that are specially designed to be used on the cellular phones.
Devices such as wristwatches, toys, game machines, stereos, video cassette recorders, and ovens contain embedded computers.
Web-Enabled Pager is also known as smart pager. It is a two way radio. It is used to send and receive messages on the Internet.
Internet appliance is also known as information appliance. It is a computer that is used to connect to the Internet from home. It contains all software applications required to connect to the Internet and browse.
Midrange server – Powerful, large computer that supports up to a few thousand computers
Mainframe – Very powerful, expensive computer that supports thousands of computers
Supercomputer – The fastest, most powerful, most expensive computer. Used for applications requiring complex mathematical calculations.
Mid-range server is larger and more powerful computer than workstation. It can serve up to 4000 connected users simultaneously. It is normally accessed via personal computer or terminal.
A device with a monitor ana keyboard is called a terminal. It is also known as dumb terminal. It has no processing power and cannot work as stand-alone computer. It has to be connected to a server.
A mainframe computer is a large computer in terms of price, power and speed. These computers have larger storage capacity. A typical mainframe computer can execute 5 million instructions per second. Examples of mainframe computers are IBM4381, NEC 610 and DEC 10 etc.
Large organizations such as banks and airlines still use mainframes for big computing jobs.
A computer that provides much of a PC’s functionality at a lower price. Network computers do not have disk drives because they get their software from the computer network.
A device connected to and controlled by a computer, but external to the computer’s central processing unit.
Super computer is a state-of-the-art machine. It is the biggest in size and the most expensive in price than any other computers. It is the most sophisticated, complex and advanced computer. It has a very large storage capacity. It can process trillions of instructions in one second. The modern super computer consists of thousands of microprocessors.
Supercomputers are used for calculation-intensive work such as weather forecasting, telephone network design, simulated car crash testing, oil exploration, computer animation, and medical imaging.
Mainframe computers are generally larger, more expensive, more powerful, and more difficult to use than PCs. Mainframes offer the capability of timesharing and communicating directly with multiple users simultaneously. PCs are small, relatively inexpensive. They generally communicate with a single user.
supercomputer? Give some examples.
Scientists and engineers often need supercomputer power to run complex modeling and simulation programs. Some large corporations use supercomputers to manage corporate data and communicate with thousands of employees.
An analog computer recognizes data as a continuous measurement of a physical property. It has no state. Analog computer is difficult to operate and use. Its output is usually displayed on a meter or graphs. It is mainly used in the field of engineering and medicine.
A digital computer works with digits. Everything is described in two states i.e. ON or OFF. The number 1 represents ON and O represents OFF state. The digital computers are very fast. These computers store results in digital format.
A hybrid computer is a combination of both analog and digital computer. Some part of processing is done on analog computer and some part on digital computer. It can accept data in both analog and digital form.
Computer can be used at home for preparing home budget, playing games, getting information, and chatting with friends.
Computer can be used in education for computer-based training, online education and research work etc.
We use computers in everyday life. Some examples are digital watches, microwave ovens, most modern cars, stereo systems, calculators, airline reservation systems, fast food restaurants, cash registers, ATM machines, and digital alarm clocks.
CBT are different program that are supplied on CD-ROM. These programs include text, graphics, and sound. Audio and video lectures are recorded on the CDs. CBT is a low-cost solution for educating people. You can train a large number of people easily.
The process of getting education through Internet is called online education. Many web sites provide online education. You can download educational material, books and tutorials without going outside. Some universities provide online lectures for the students.
Computers can be used for research purposes. Different research scientist can share their research using Internet. Many websites are developed for research activities. The students are young researchers can benefit from such websites.
Computer can be used in business and industry for automated production system, design systems, stock control, accounts and payroll system, fax, email, video conferencing, word processing, spreadsheet and databases applications.
Many companies use video conferencing to deal with other companies. In video conferencing people residing at various places can talk with each other. They can see one another. It is very useful in this busy age. It prevents a lot of time and costs.
Computer can be used in medical field for hospital administration, recording medical history, monitoring system, life support systems and diagnosis of diseases.
Information technology is a technique used in the creation, storage, and dispersal of data, information and creation of knowledge.
All computers contain a processing unit (CPU). CPU is like the brain of computer. A computer without a CPU cannot work.
The purpose of the central processing unit is to perform the processing actions of the computer. This includes arithmetic calculations and logical operations. Other names for the CPU are the processor, the chip, and the microprocessor.
Secondary storage is relatively permanent storage. It is external to the computer but can be read by the computer. It can store huge amounts of data.
Information technology is a technique used in the creation, storage, and dispersal of data, information and creation of knowledge. Computer is an important component of information technology. It makes possible fo use information technology for solving problems.
Three components of information technology are as follows:
Computers – Electronic systems that can be instructed to accept, process, store, and present data and information.
Communications Networks – The interconnection of different locations through a medium that enables people to send and receive information.
Know-how – Know-how is the capability to do something properly. Information technology know-how consists of the following.
Communication networks allow people and businesses to interact with. It includes hardware, programs, and information. Information technology has become revolutionary through the use of communication networks. Information can be transferred from one place to another easily and quickly.
Know-how is the capability to do something properly. Information technology know-how consists of the following:
1. Familiarity with the tools of information technology including the Internet.
2. Possession of the skills needed to use these tools
3. Understanding of using information technology for problem-solving & creating opportunities.
Know-how is a component of information technology because people should know the use of information technology to solve problems. They should also know how information technology can create opportunities for them.
The instructions written in a program derive the hardware to convert data into information.
Users are people who use information technology in their jobs or personal lives. IT professionals are responsible for acquiring, developing, maintaining, or operating the hardware and software. associated with computers and communication networks.