nBit

n-bit is a general term used in computing to describe the width of a data path, register, or memory addressing, with n representing a positive integer number of bits. It denotes how many bits are used to represent values, perform arithmetic, and address memory in a system.

The width of n bits determines the range of representable values. For unsigned numbers, an n-bit field can represent 0 to 2^n minus 1. For signed numbers (commonly using two's complement), the range is typically −2^(n−1) to 2^(n−1)−1. The width also constrains the maximum direct addressing capacity, since memory addresses are encoded with n bits, yielding 2^n possible addresses in a simple model. In practice, many systems use additional addressing mechanisms, but the concept illustrates the link between width and capacity.

Common n-bit widths include 8-bit, 16-bit, 32-bit, and 64-bit. They reflect historical and architectural choices: 8-bit systems were widespread in early microcontrollers; 16- and 32-bit architectures became dominant in later decades; 64-bit processors are standard in modern personal computers and servers. Some processors employ mixed-width designs, performing smaller-width operations on a larger datapath.

In software and hardware design, n-bit describes registers (n-bit registers), data buses, and instruction encodings. Programming languages and application binary interfaces often specify fixed widths for integers (for example, 32-bit or 64-bit types), with behavior upon overflow determined by language rules.

In cryptography, n-bit denotes the size of blocks or keys (for example, 128-bit blocks or 256-bit keys), where the width influences security properties and performance. Endianness and bit-level operations are additional considerations when working with n-bit values.