Quality of Service (QoS) refers to the overall performance of a network or service, particularly in terms of its ability to deliver data reliably and efficiently. It involves managing bandwidth, latency, and packet loss to ensure that users experience minimal disruptions. QoS is crucial for applications that require consistent performance, such as video streaming, online gaming, and voice over IP (VoIP). To achieve QoS, network administrators can prioritize certain types of traffic, ensuring that critical applications receive the necessary resources. This can involve techniques like traffic shaping and bandwidth allocation, which help maintain a smooth user experience even during peak usage times. Effective QoS management is essential for maintaining user satisfaction and optimizing network performance.