What is a computer?
A computer is an electronic machine that performs tasks, such as calculations or electronic communication, under the control of a set of instructions called a program.
Programs usually reside within the computer and are retrieved and processed by the computer’s electronics. The program results are stored or routed to output devices, such as video display monitors or printers. Computers perform a wide variety of activities reliably, accurately, and quickly.
Basic Parts of Computer
The system unit is the core of a computer system. Usually it’s a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU), or microprocessor, which acts as the “brain” of your computer. Another component is random access
memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off.
Your computer has one or more disk drives—devices that store information on a metal or plastic disk. The disk preserves the information even when your computer is turned off. Also computer storage includes hard disc drive, floppy disc, flash disc CD and DVD.
A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It’s small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless. A mouse usually has two buttons: A primary button (usually the left button) and a secondary button. Many mice also have a wheel between the two buttons, which allows you to scroll smoothly through screens of information.
A keyboard is a tool that is used for typing like a typewriter. A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys: The function keys, found on the top row, perform different functions depending on where they are used.
The numeric keypad, located on the right side of most keyboards, allows you to enter numbers quickly. The navigation keys, such as the arrow keys, allow you to move your position within a document or webpage.
A monitor is the screen on your computer that you look at when you are on the computer. A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures.
There are two basic types of monitors: CRT (cathode ray tube) monitors and the newer LCD (liquid crystal display) monitors.
A printer transfers data from a computer onto paper. You don’t need a printer to use your computer, but having one allows you to print e-mail, cards, invitations, announcements, and other material. Many people also like being able to print their own photos at home. Also printer can be defined as; a machine that puts things from the computer onto paper.
Speakers are used to play sound. They can be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.
To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computerin formation over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher-speed modems are usually separate components.