A Media Access Control address (MAC 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. A MAC address is a 48-bit number that 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 can be used to control access to a network. For example, a network administrator can configure a router 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 tool called a MAC address tracker to see which devices are connected to a network and where they are located.