Bit is a neologism made up of binary and digit and is the smallest digital information unit. A bit characterizes a binary, i.e. two-valued, dimensionless state. If the state is present, the bit has the value 1, if the state is not present, it has the value 0. A bit therefore only knows two states: 1 or 0, yes or no, open or closed.
These two states are the basis for all digital technology. With this two-valued system, arithmetic operations can be executed by means of dual arithmetic, and signals can be mapped and transmitted in digital form.
If two bits are combined in a group, this is called a dibit, three a tribit and four a quadbit, also called a nibble or half byte. Such bit groups are mainly used in modulation, for example in modems. A bit group of eight bits forms a byte (B).