ANALOGY: computer~~mailroom

•Imagine a mailroom with 256 mailboxes, numbered 0 through 255. •Each mailbox can contain only a single piece of paper with a number from 0 through 255 written on it. •Why 256?  Techie nomenclature:
One byte = 8 bits.  A bit can be either “0” or “1”.  28 = 256 possible combinations of 8 bits. So every number can be represented.