2. Processing Devices,Output Devices

Processing Device       

The CPU (Central Processing Unit) is the processing device that works on input and sends the result to the output devices. The CPU is a chip which is placed inside the CPU box.

CPU is also called the “brain” of a computer as it is responsible for all the work done. A CPU is further divided into three parts: ALU, CU and MU.                                                 

Arithmetic and Logic Unit (ALU)

ALU does all the arithmetic calculations like addition, subtraction, multiplication, division etc. It also does comparisons like greater than, less than, equal to etc.

Control Unit (CU)

CU coordinates and controls all the parts of the CPU. The CU gets the data and instructions from the memory unit and passes them to the ALU in a step by step manner.

Memory Unit (MU)

The CPU also has a memory like human beings. It stores the data and instructions that you give to the computer along with the results of the processing.

Output Devices

The devices that show us the result of processing done by the CPU are called output devices. The result can be in any of these forms : display on the monitor, print by the printer and sound from the speakers. The  output which is displayed on the screen of a monitor is called the soft copy. A printout of the soft copy on paper is called the hard copy of the output. Some of the commonly used output devices are:

Monitor

A monitor looks like a television. It is also known as the Visual Display Unit or VDU. The monitor shows the data that you input and its result (output) after the computer processes it.

Speakers

Speakers are used to hear music, voice and sound on a computer.

 Headphones

Headphones are used to listen to music and sound without disturbing others as they are worn by an individual. But wearing them for a long time can affect your hearing power and cause damage to your ears.

Printer

A printer is used to print the result of the work done by the computer on paper. We can print documents, drawings, images etc. in black and white as well as in the colour using a printer. There are two type of printers:

·        Laser Printer - It uses a laser beam to print the hard copy.

·        Inkjet Printer – It sprays ink on the paper to print the hard copy.

Plotter

A plotter is used to print big sketches, diagrams and maps on long sheets of paper. They are used by engineers, architects, scientists and designers.

Projector

A projector projects or displays data from a computer screen on a larger screen or surface for the audience.

Smartboard

A smartboard is used in classrooms as a teaching tool. It is an interactive board that displays information with the help of a projector.