What does a MAC address represent?

• A. A digital certificate for authentication
• B. Media Access Control Address - machines physical address
• C. A type of memory address
• D. A routing protocol identifier

Answer: (B)

A MAC address is the hardware address assigned to a network interface controller, a unique identifier baked into the device to identify it on a local network. It’s used at the data link layer to deliver frames to the correct physical device on a LAN; switches learn and use these addresses to forward traffic within the same network segment. It’s typically 48 bits long and displayed as six hex octets, often written with colons or hyphens. This is not a digital certificate used for authentication, not a memory address that points to system RAM, and not a routing protocol identifier used to exchange routing information between routers. On the IP level, ARP maps an IP address to its corresponding MAC address so that IP traffic can actually reach the right device on Ethernet.