The phrase “input devices” itself tells us that the device used to put something in is called an input device.
In the context of computers, we can say that it is made up of two parts i.e. hardware and software. Input and output devices come under the category of computer hardware. So the devices used to put in the data and information in the computer, are known as input devices. On the other hand, output devices are those devices that show us the results after the data and information have been processed.
Without the input devices, a computer will not be able to get any data and information, and will remain only as a display device. As a result we will not be able to use a computer for our help. There are number of input devices used in the computer for e.g.:- keyboard, mouse, joystick, lightpen, touchpad, touchscreen, trackball, webcam, scanner, microphone, barcode reader, etc. Without the help of above mentioned devices we cannot send information and data to the central processing unit of a computer. So input devices are first and foremost requirements for a computer system.