What does Software-Defined Networks (SDN) primarily decouple?

Software-Defined Networks (SDN) primarily decouples network control and forwarding functions. This architectural approach separates the network's control plane, which decides how traffic is managed, from the data forwarding plane, which is responsible for transferring packets from one point to another in the network.

By creating this separation, SDN allows for centralized network management, providing greater flexibility, scalability, and programmability. Network operators can adjust and optimize traffic flow based on real-time data and application demands without changing the underlying hardware, leading to more efficient use of resources and improved network performance.

In contrast, the options that focus on areas such as appliance management, networking hardware and software, or data storage and retrieval do not capture the fundamental innovation of SDN, which is primarily concerned with the delineation between control and data planes to enhance network intelligence and operational agility.