What is the main function of a network switch?

The main function of a network switch is to filter and forward packets between network segments. This process involves receiving data packets from one device on a local area network (LAN) and determining the appropriate destination for each packet based on its MAC (Media Access Control) address. By doing this, a switch can intelligently send data only to the device that needs it, rather than broadcasting it to all devices on the network. This targeted data transmission enhances network efficiency and reduces congestion, allowing for faster communication among connected devices.

The ability of a switch to maintain a MAC address table, which maps addresses of devices to their corresponding ports, is crucial to its operation. When a packet arrives, the switch looks up the destination address in its table and forwards the packet only to the correct port, ensuring that traffic is directed efficiently. This is a key characteristic that distinguishes switches from simpler devices, such as hubs, which indiscriminately send incoming data to all ports.

The other options describe different network functions: converting signals pertains more to media converters, measuring network performance relates to network monitoring tools, and amplifying signals is typically associated with repeaters or signal boosters. Therefore, the filtering and forwarding of packets is what fundamentally defines the operation of a network switch.