Definition
Quality of Service (QoS) refers to a set of technologies and techniques used to manage network traffic and ensure predictable performance for critical applications. It works by prioritizing certain types of data packets over others, allocating bandwidth, and controlling latency and jitter. On the job, QoS is vital for maintaining application responsiveness and user experience, especially in environments with limited network resources. For instance, a VoIP call might be prioritized over a large file download to prevent dropped calls and garbled audio. While often discussed alongside network security, QoS is primarily a performance management tool, not a direct security control. Understanding QoS is beneficial for certifications like CompTIA Network+ and CISSP.