Quality of Service (QoS) refers to the overall performance of a service, particularly in telecommunications and computer networks. It involves managing network resources to ensure a certain level of performance, reliability, and availability for users. QoS is crucial for applications that require consistent data transmission, such as video streaming, online gaming, and voice over IP (VoIP). To achieve Quality of Service, network administrators use various techniques to prioritize traffic, manage bandwidth, and reduce latency. This ensures that critical applications receive the necessary resources while minimizing disruptions. By implementing QoS, organizations can enhance user experience and maintain efficient operations in their networks.