bytes

A byte is a unit of digital information used in computing. It is typically eight bits in modern systems and serves as the standard unit of memory and data size. The term originated as a contraction of by eight, referring to the number of bits in a single unit. Historically, some early machines used bytes of different lengths, but eight bits is now the global convention. The term octet is used in some standards to emphasize eight bits.

Bits and bytes: A bit is the smallest unit, 0 or 1. A byte usually represents a character or small integer, depending on encoding. The uppercase B denotes a byte, while lowercase b denotes a bit. Data sizes are expressed in bytes and their multiples: KB, MB, GB, TB. Some contexts use decimal prefixes (1 KB = 1000 bytes); others use binary prefixes (1 KiB = 1024 bytes).

Character encoding: Many sets map a single byte to a character (8-bit encodings such as extended ASCII). Unicode uses variable-length encodings: UTF-8 encodes 1–4 bytes per character; UTF-16 uses 2 or 4 bytes. Memory and disk capacities are described in bytes, and network data rates are expressed in bytes per second.

History and usage: In early hardware, a byte did not always equal eight bits, and memory addressing could be organized around word sizes larger than a byte. Since the 1960s–1980s, eight-bit bytes became the predominant standard in many architectures, reinforcing the byte as the basic unit of data. Today, bytes are the fundamental reference for data size in programming, networking, and storage.