Quality of Service (QoS)
is a catchall term for the technologies that are deployed on networks and on servers to ensure that the service delivered meets the stated service level agreements. It uses various technologies to ensure that infrastructure availability is maintained, that network throughput is acceptable, that latency is minimised, and that errors and security threats are detected and dealt with. Certain types of network traffic can also be prioritised. This can be used to ensure that traffic that is critical is delivered in favour of other, less critical network traffic.