A Bit is the most basic unit of information that exists in a binary numbering system. Bit is short for BInary digiT. That means that there are only two states, usually expressed as some variation of high and low current, which stand for the two binary volumes 0 and 1. They can also be expressed as yes/no expressions, or either/or ones. One such expression is one bit, and multiples of them are what, combined together, makes every file, program and computer function that we use.