Binary:
Binary (or base-2) is a numeric system that only uses two digits 0 and 1. It is compare 0 or 1 which is called as bits. Literal meaning of bit is if I get bit of information I can catch the thief. So bit means always compare 2 states.
There 4 type of numbering systems available in the world.
CPU (central processing units) knows only in binary formats. So every music notes are converted to binary base and start playing the music.
As I mention earlier bit means compare the two starts 0 or 1. In Normal English communication if I get a bit information and I can solve the issue. So bits means always comparing two stated. It can be either true or false, 0 or 1 and South Pole or North Pole etc.