Latency is the amount of time a message takes to traverse a system.
Measuring Network Latency
Network tools like ping tests and traceroute measure latency by determining the time it takes a given network packet to travel from source to destination and back, the so-called round-trip time. Round-trip time is not the only way to specify latency, but it is the most common.
Latency depends on the speed of the transmission medium (e.g., copper wire, optical fiber or radio waves) and the delays in the transmission by devices along the way (e.g., routers and modems). A low latency indicates a high network efficiency.
Two key elements of network performance are bandwidth and latency. The average person is more familiar with the concept of bandwidth as that is the one advertised by manufacturers of network equipment. However, latency matters equally to the end user experience as the behavior of satellite Internet connections illustrates.
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