Imput is a meaning, entrance or changes wich are inserted into a system and can activate or modify the process.
Imput is also your keyboard and mouse imputing what you are doing
Output is either an exit or changes wich exit a system and can activate or modify a process.
A storage device is used for recording or storing information. It can hold any sort of information you put into it. An electrical storage devices requires an electric power sorce to hold and recive data stored in it.