difference between input and output device

To understand the difference between an input and output device, you must understand the difference between inputand output. Any information or data that's entered or sent to the computer  to be processed is considered input and anything that is displayed from the computer is output. Therefore, an input device such as a computer keyboard is capable of having information sent to the computer, but does not display (output) any information. An output device such as a computer printer can print information from the computer but does not send any information (input) to the computer.