128-bit

In computer science, 128-bit is an adjective used to describe integers that are at most 128 bits wide, or to describe CPU architectures based on registers, address buses, or data buses of that size.

The term "128-bit" can be used to describe the size of any of the following:

• A data unit.
  • A 4-bit unit (a hexadecimal digit) is called a nibble or nybble.
  • An 8-bit unit is called an octet (or a byte).
• A CPU's registers used to hold memory addresses and other data, as well as the ALU that operates on those registers.
  • Data units of that size are called words.
  • A 128-bit CPU can process 128 bits at a time.
• Memory addresses.
• Data transferred on each read or write of the memory.