Quality of Service (QoS) is a technology for managing network traffic in a cost-effective manner to enhance user experiences for home and enterprise environments. It allows us to measure bandwidth, detect changing network conditions (such as congestion or availability of bandwidth), and prioritize or throttle traffic. For instance, QoS technologies can be applied to control the impact of latency-insensitive traffic (such as bulk data transfers) and to prioritize traffic for latency-sensitive applications (such as voice or video). The main goal of QoS is to provide preferential delivery service for the applications that need it by ensuring sufficient bandwidth, controlling latency and jitter, and reducing data loss. It also ensures that time-sensitive and mission-critical applications have the resources they require, while allowing other applications access to the network. Also gives administrators control over network resources and allows them to manage the network from a business, rather than a technical, perspective. Thus, overall improves user experience.