QoS Architecture and Models refer to the frameworks and methods used to design and implement Quality of Service in network environments. These architectures define how network devices classify, prioritize, and manage traffic to ensure reliable communication. Common QoS models include Best Effort, Integrated Services (IntServ), and Differentiated Services (DiffServ). Each model provides different approaches for handling bandwidth allocation, latency control, and traffic prioritization. QoS architectures use techniques such as traffic classification, queuing, shaping, and congestion management to optimize network performance. They help ensure smooth delivery of critical applications like voice, video, and cloud services. QoS Architecture and Models are essential for building scalable, stable, and high-performance enterprise networks.