Which network device maintains a record of MAC addresses to direct data packets appropriately?

The correct answer is a switch. A switch operates at the data link layer of the OSI model and is specifically designed to facilitate the effective communication within a network by directing data packets based on MAC addresses. When a switch receives a data packet, it examines the destination MAC address, referencing its MAC address table, which contains a record of each device's MAC address and the corresponding port. This allows the switch to forward the data packet only to the intended recipient, reducing network traffic and enhancing overall efficiency.

In contrast, a server primarily provides resources, services, or data to other computers over the network but does not perform the function of directing data packets based on MAC addresses. A router, while also capable of directing data packets, operates primarily at the network layer and focuses on IP addresses, making it distinct from the function performed by a switch. Lastly, a bus is a physical network architecture rather than a device, and does not manage MAC addresses or route data between devices.