Final answer:
A four binary digit long unit of data is called a nibble, which can represent sixteen possible values, from 0 to 15.
Step-by-step explanation:
A unit of data that is four binary digits long is known as a nibble. In digital data transmission and computer processing, data is represented as a sequence of binary ones and zeros, where each binary digit is called a bit. Four bits, or a nibble, can represent sixteen possible values (24), ranging from 0000 to 1111 in binary, which corresponds to 0 to 15 in decimal notation. This term isn't as commonly used as the byte, which is made up of eight bits. The byte is a more standard unit for measuring digital information, and when we discuss larger quantities, such as one million bytes, we refer to it as a megabyte (MB)