What is a MAC Address?

A MAC address, or Media Access Control address, is a globally unique identifier that is assigned to a network interface for communication on the physical network segment. It is a critical component in computer networking, as it facilitates the identification of devices on a local network. Each MAC address is hard-coded into the hardware of a device’s network interface card (NIC) and is represented as a 12-digit hexadecimal number, ensuring that no two network interfaces have the same MAC address within the same local network.

This unique identifier is essential for the Data Link layer of the OSI model, allowing devices to identify and communicate with each other within the same network. It plays a vital role in various networking protocols, such as Ethernet, where it helps in the proper routing of data frames on a local network. By utilizing MAC addresses, devices can reliably send data to the correct recipient without interference or confusion from other devices.

The other options present concepts that do not accurately represent what a MAC address is. A temporary identifier for network sessions pertains to protocols like DHCP or the concept of temporary IP addresses. An encryption key for secure communication relates to cryptographic protocols and the security of data, while a protocol used for network routing refers to communication methods such as TCP/IP or routing protocols like