Editing Parallel communication (section)

{{short description|Method of data transmission in which bits are conveyed in parallel}}
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[[Image:Serial and Parallel Data Transmission.svg|thumb|right|300px|Parallel versus serial communication]]

In [[data transmission]], '''parallel communication''' is a method of conveying multiple binary digits ([[bit]]s) simultaneously using multiple conductors. This contrasts with [[serial communication]], which conveys only a single bit at a time; this distinction is one way of characterizing a [[communications link]].

The basic difference between a parallel and a serial [[communication channel]] is the number of [[electrical conductors]] used at the [[physical layer]] to convey bits. Parallel communication implies more than one such conductor. For example, an 8-bit parallel channel will convey eight bits (or a [[byte]]) simultaneously, whereas a serial channel would convey those same bits sequentially, one at a time. If both channels operated at the same [[clock speed]], the parallel channel would be eight times faster. A parallel channel may have additional conductors for other signals, such as a [[clock signal]] to pace the flow of data, a signal to control the direction of data flow, and [[Handshake (computing)|handshaking]] signals.

Parallel communication is and always has been widely used within [[integrated circuit]]s, in [[peripheral]] buses, and in memory devices such as [[random-access memory|RAM]]. Computer system buses, on the other hand, have evolved over time: parallel communication was commonly used in earlier system buses, whereas serial communications are prevalent in modern computers.