From The Free On-line Dictionary of Computing: (http://www.foldoc.org/, Editor Denis Howe)
1. The time it takes for a packet to cross a network connection, from sender to receiver.
2. The period of time that a frame is held by a network device before it is forwarded.
Two of the most important parameters of a communications channel are its latency, which should be low, and its bandwidth, which should be high. Latency is particularly important for a synchronousprotocol where each packet must be acknowledged before the next can be transmitted.