Introduction to Computers

A Computer works only when there is electric power. Computers can make decisions according to the given program only.

A Computer consists of three parts. They are

     1.        Input Devices

     2.        Processing Device (C.P.U)

     3.        Output Devices

1. Input Devices

      These are the devices used to feed data into a computer. 

Ex: Keyboard, Mouse, Scanner, Joystick

Keyboard: It is an input device, which is similar to that of a  typewriter, plugged into the CPU by means of a wire. It has about 108 keys, which are classified into alphabetical keys, numerical keys, function keys and special keys. Each key has some specific

Mouse: It is an input device also called as a pointing device, which is used to do the    movement on the screen quickly. It has a plastic ball on its lower side and two or three buttons on the upper side.

2.  C.P.U (Central processing unit)

It is the brain of the computer. It Consists of 3 parts

1.  MU ( Memory Unit)

It is used to store the information.

2.   A. L. U (Arithmetic Logic nit)

It is used to perform mathematical operations

e + ,-, *, I etc., and logical operations like> . <, = .,

3.   C U (Control Unit)

It controls and co-ordinates all the activities of a computer.

3.   Output Device

      These are the devices used to get the processed data from the CPU.

            Eg: Monitor, Printer, Speaker.  

Monitor: It is an output device, which resembles a TV. It displays the mouse movements and the data e feed rough the keyboard. There are two types of monitors. Namely monochrome

(black and white) and color monitor.  

Printer: A printer is a output device which is use to get the print out on a paper known as hard copy. The different types of printers are Dot matrix printers, Inkjet printer, Laser printer.

            

Speaker: It is an output device used to get the sound or Audio