Nibble

A four-bit aggregation in computer:

Nibble (also written as Nybble, or Nyble and also known as Hex Digit or Hexit)

In computer, a nibble is a four-bit aggregation, or half a byte (half an octet). As a nibble contains 4 bits, there are sixteen possible values, so a nibble corresponds to a single hexadecimal digit, and sometimes it is referred to as a hex digit or hexit.