The key component of Sophos XG Firewall architecture is the Data Plane. This part of the architecture is crucial because it is responsible for processing all the data traffic that passes through the firewall. Essentially, the Data Plane handles the actual inspection and management of network traffic, applying the security policies that have been configured by the user. In the context of firewall architecture, the Data Plane operates independently of other components, allowing it to efficiently manage incoming and outgoing traffic based on the specified security rules. By focusing on the Data Plane, Sophos XG Firewall ensures effective threat mitigation, user policy enforcement, and overall network performance. The other components, such as the Access Plane, Management Interface, and Control Layer, serve specific purposes in the architecture. However, they do not directly handle the actual data traffic in the same manner as the Data Plane does. The Access Plane focuses on user authentication and access control, the Management Interface is used for configuration and management tasks, and the Control Layer oversees the deployment of policies and framework. Each of these components plays an important role in the overall functionality of the firewall, but it is the Data Plane that is pivotal for the core operation of traffic management and security enforcement.