Input in a computer is when the information comes in to the computer like a command and the output will be the result of what the command gives you back.
The monitor is what is connected to the computer itself and this shows all the graphics and the information form the computer.
The monitor is similar to a television but a lot better as it can show information at a much higher resolution.
Stands for the central processing unit. That is what it does it processes all information and commands from programs.