THE COMPUTER HARDWARE
A Device used for observing, checking or keeping a continuous record of something. a television receiver used in a studio to select or verify the picture being broadcast from a particular camera.observe and check the progress or quality of (something) over a period of time; keep under systematic review.
In computing input/output or I/O is the communication between an information proceccing system (such as a computer) and the outside world, possibly a human or another information processing system. inputs are the signals or data received by the system, and outputs are the signals or data sent from it.