mid-15c., from Middle English pak "bundle" (see pack (n.)) + diminutive suffix -et; perhaps modeled on Anglo-French pacquet (Middle French pacquet), which ultimately is a diminutive of Middle Dutch pak. A packet boat (1640s) originally was one that carried mails. Packet-switching attested from 1971.
The unit of data sent across a network. "Packet" is a generic term used to describe a unit of data at any layer of the OSI protocol stack, but it is most correctly used to describe application layer data units ("application protocol data unit", APDU).
See also datagram, frame.
(1994-11-30)