A MAC address (Media Access Control address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. MAC addresses are used in most IEEE 802 networking technologies, including Ethernet, Wi-Fi, and Bluetooth. Each MAC address is 48 bits long and is typically written in hexadecimal format, such as 00:11:22:33:44:55.
MAC addresses are important for several reasons. First, they allow network devices to identify each other on a network. Second, they are used to control access to a network. For example, a router can be configured to only allow devices with specific MAC addresses to connect to the network. Third, MAC addresses can be used to track the movement of devices on a network. For example, a network administrator can use a MAC address to track the location of a stolen laptop.