Can you explain the concept of quality of service assurance in systems and its significance?

Quality of Service (QoS) is a set of methods and mechanisms that guarantee a certain level of performance and reliability in systems, especially in networks and distributed applications. QoS is important to ensure that critical services receive priority, minimize delay, packet loss, and ensure bandwidth.

For example, in VoIP calls, QoS helps ensure minimal delay and stable sound quality by prioritizing call traffic during data transmission over the network. In DevOps, this may involve setting up monitoring, load balancing, and resource prioritization to maintain SLA (Service Level Agreement).