Quality of Service (QoS) is a technology that manages and prioritizes certain types of data traffic on a network with the goal of reducing packet loss, latency and jitters for that specific type of network traffic or protocol (for example VoIP).
QoS controls and manages network resources by setting priorities for specific types of data on the network. QoS optimizes the network by managing bandwidth and setting priorities for applications that require more resources than others. QoS is an underutilized tool allowing system administrators to adjust the network settings, splitting up the available bandwidth between applications. With proper QoS rules in place, you can ensure that, for example, streaming Netflix doesn’t buffer because a large file is downloading at the same time, or that your work laptop isn’t slow when trying to meet that last minute deadline while your roommates are playing games online.
Source: TechTarget, HTG
Related Term: Bandwidth