Quality of Service which is most commonly known as QoS is a telephony term which when simplified means you configure your network to give priority to voice traffic. In it’s simplest form it works like this:
If you have some telephone calls in progress using VoIP and another staff member starts downloading a very large file that quality of the phone conversations will normally deteriorate and start to sound stuttered. When QoS is turned on or configured on your network the quality of voice calls remains excellent, but the file will be downloaded slower – priority is given to the voice traffic on your network.
This feature can be as simple as clicking on a check box but if you want some extra reading feel free to visit the Wikipedia page on QoS and you’ll sound like a networking pro in now time!