- noun data transmission one bit at a time (this is the normal method of transmission over longer distances, since although slower, it uses fewer lines and so is cheaper than parallel)
- noun data transmitted one bit at a time. This is the usual method of transmission over long distances, since, although slower, it uses fewer lines and so is cheaper than parallel transmission.
- The transmission of bits, characters, or data units one at a time in sequence. This contrasts with parallel transmission, in which multiple bits, characters, or data units are transmitted simultaneously. Also called serial data transmission.