Capacity

Capacity, in relation to computers, the amount of information a computer or an attached device can process or store. With respect to specific parts of a computer system:

Disk capacity is the total number of bytes (characters) a disk can hold. Because the operating system of a computer requires some space on the disk for its own use, and because files on a disk are stored in blocks rather than byte by byte, disk capacity is greater (although not significantly greater) than available storage space.

Channel capacity is the maximum speed at which a communications channel can transfer data within or between computers.

Memory capacity is, in terms of microcomputers, usually considered the amount of random access memory (RAM) in a computer. Often, however, the term is used to describe the amounts of both RAM and ROM (read-only memory).

Processing capacity refers to the maximum number of operations that a processor can handle in a given unit of time, often expressed in MIPS (millions of operations per second) or FLOPS (floating-point operations per second).

Register capacity is the total number of bits or bytes that a register in a microprocessor can store.