I choose Input and Output Device, Because It's easy to see it in everyday life.
Before a computer can process your data, you need some method to input the data into the machine. after the computer has processed your data, you often need to produce output of the results. This output could be a display on the computer screen, hardcopy on printed pages, or even the audio playback of music you composed on the computer. For example, 1).Keyboard(input) The computer keyboard is used to enter text information into the computer, as when you type the contents of a report. The keyboard can also be used to type commands directing the computer to perform certain actions. Commands are typically chosen from an on-screen menu using a mouse. 2).Monitor(output) is a device that is required and is used to display the output. Whether it be in the form of text, graphics, animations, slides. 3).Printer(output) is one of the types of output devices. Used for printing data from a computer onto paper.