A simple model of a computer:

But this also a model for a paper shredder or a person.    Our inputs are our senses.  Our processor is our brain.  Our outputs are the ways we can change or communicate with the outside world what is in our brains- what we are thinking, feeling, or what we need to do with our bodies.   What does the computer processor look like?

What does one storage cell (byte) look like?

It can store a pattern that represents a letter or simple number, but a few thousand (K) or a few millions (Meg) or a few billions (Gig) can represent a picture, video, song, or anything you can imagine.  The process of turning anything into a series of ons and offs is called digitization.  There are two kinds of bytes- those that can be changed (RAM)  and those that are fixed with the same pattern (ROM)

T

This is all we need.  If we want to turn the computer off, however, we need away for the computer to remember what was in its brain.  We write something down if we want to remember it for later.  The computer has secondary storage (CD, DVD, hard drive, flash drive, etc..) to remember things without power so it can be recalled the next time it is needed.