Bit can have different meanings:

• A digit in binary notation, either 0 or 1. This is like a light switch; either there is light or there is not.
• A unit of measurement for the amount of data. This will be a multiple of 1 bit; only integers are allowed.
• As a unit of measurement for information. In this context, 1 bit is the amount of information that is present in the selection of two equally probable options. In this meaning, real values as multiples are possible.
• A small amount of anything either literal or theoretical.