Latency (engineering)
Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. In communications, the lower limit of latency is determined by the medium being used for communications. In reliable two-way communication systems, latency limits the maximum rate that information can be transmitted, as there is often a limit on the amount of information that is "in-flight" at any one moment. In the field of human-machine interaction, perceptible latency has a strong effect on user satisfaction and usability.
Read more about Latency (engineering): Audio Latency, Operational Latency, Mechanical Latency, Computer Hardware and Operating System Latency, Latency in Simulators and Simulation