Keying devices: These devices enter data into the computer through a set of keys like keyboard, keypad.These are again classified based on the kind of input they give:
Input devices: These are the kind of hardware used to give commands or instructions to the central processing unit of the computer system.It is broadly classified into five types. Computer hardware comprises all the physical components of the system like the central processing unit or the CPU (which includes the motherboard, sensors embedded in it), monitor (displays the content), mouse, keypad, joystick, power supply unit, graphics card, web camera, and such others. Computer hardware is one of the two parts that make the complete working of the system, and the other is the computer software.