About a computer

It consists of hardware of equipment with a physical computer, and software of the program which operates equipment, or data, and operates.

In a personal computer, hardwares, such as a main part, and a display, a printer, and software, such as OS (operating system), and a word processor, a spreadsheet, are used.

People and a personal computer

There is same element in a personal computer with people.
The 1st is an input-element. If people's eye, nose, and ear are seen, smelled and heard, it is to be said that various situations are known. In a personal computer, a keyboard, a mouse, a scanner, etc. are the same input equipment as these similarly.
Next, it is an output-element. People's mouth generates sound and other things are told about it. This is the same output unit as the role of a display or a printer in a personal computer.
Otherwise, it is an input-and-output-element. People's hand and foot are the output-element which moves and carries out something to the input-thing for which a thing is touched or the thing is investigated. This is disk equipment in a personal computer.