Computer memory is a temporary storage area. It holds the data and instructions that the Central Processing Unit (CPU) needs. Before a program can run, the program is loaded from storage into the memory. This allows the CPU direct access to the computer program. Memory is needed in all computers.
A computer is usually a binary digital electronics device. Binary means it has only two states. On or Off. Zero or One. In a binary digital computer transistors are used to switch the electricity on and off. The computer's memory is made from lots of transistors.
Each on/off setting in the computer's memory is called a binary digit or bit. A group of eight bits is called a byte. A byte is made from two nibbles of four bits each. Computer scientists made up the words bit and byte. The word bit is short for binary digit. It takes bi from binary and adds the t from digit. A collection of bits was called a bite. The computer scientists changed the spelling to byte to avoid confusion. When the computer scientists needed a word for half a byte, they thought nibble, as in half a bite, would be a fun word to choose.[1]
nibble carries on the "edible data" metaphor established with bit and byte