History of Computers

The use of computers basically started in the 20th century. Scientists used it for doing mathematical calculations as computers saved their time which was earlier spent in adding numbers.

"Charles Babbage" is popular as "the father of the computer", as he invented the first mechanical computer.

Types of Devices Used in Computer

There are two types of devices used in a computer:

1.Input devices:

The devices that are used to enter or insert data into the computer are known as input devices.

Some of the input devices are:

• Keyboard: it is used to enter the alphabets, numbers and symbols into the computer.

• Scanner: It is used to scan the documents which are then entered into the computer as images.

 There is a special type of input device which is known as 'Pointing device'. It is used to specify a certain position in space Example: joystick, mouse.

• Mouse
     

2.Output devices:

The devices that receive data from the computer in order to perform a task are known as output devices.

Some of the output devices are:

• Monitor: It is used to display the information which has been entered using the input devices.

• Printer: It is used to print the information that has been entered into the computer.

   How to Start a Computer

There are several ways to start a computer, but the most commonly used method is as follows:

• Step 1: Plug the computer in a power source.
• Step 2: Find the power of the computer which is at the CPU of the computer.

• Step 3: Press the power button.

How to switch off the computer

Step 1: Click the start button at the bottom left corner on the screen.

Step 2: A list will appear. Now click on shut down button on the bottom right corner.

Step 3: If you have left programs or files open, you will get a message like this:

Now you can do two things:

• Either a click cancels and closes all the programs, and then again follows the above steps.
• Or click on the force shut down and it will automatically close all the programs. 

Recap

• Charles Babbage is known as "the father of the computer".
• Input devices are used to insert data into the computer. Example: keyboard, mouse.
• Pointing devices are a special type of input device used to specify the position.
• Output devices are used t receive data from the computer. Example: printer.
• To start a computer, press the power button the CPU.
• To switch off a computer, click on the start button on the bottom left corner of the screen and then click on the shutdown button on the bottom right corner of the screen.