Final answer:
A network switch uses MAC addresses to send data between nodes on a LAN and is essential for directing network traffic accurately.
Step-by-step explanation:
A network switch uses unique, hard-coded physical addresses, known as media access control (MAC) addresses, to send data between nodes. Each device on a network has a MAC address which is assigned to the network interface card (NIC) by the manufacturer and is used by the network switch to direct traffic within a local area network (LAN). When a device attempts to communicate over the network, the switch uses the MAC address to ensure that the data is sent to the correct destination node. This system is crucial for managing traffic on a network and ensuring that data packets reach their intended recipients efficiently.