Four Main Types of Hardware are. Input Device Use to enter information into the computer. Example: Keyboard, mouse,joystick, scanner, voice recognition, touch screen, microphone, light pen, and stylus.Besides the monitor, keyboard and mouse, which are effectively output devices, you will require four basic hardware components in the case of your PC: the motherboard, central processing unit, hard disk drive and power supply.Hardware refers to the physical elements of a computer. Also referred to as the machinery or the equipment of the computer. Examples of hardware in a computer are the keyboard, the monitor, the mouse and the processing unit However, most of a computer's hardware cannot be seen; It's inside the computer case.