The standard MAC address used by Ethernet and Wi-Fi devices is 48 bits long.
A 48-bit MAC address is normally written as six groups of two hexadecimal digits, such as 00:1A:2B:3C:4D:5E. The address operates at the data-link layer and helps identify a network interface on a local network segment.
The first 24 bits traditionally identify the manufacturer through an organizationally unique identifier, while the remaining bits identify the interface. Modern devices can also use locally administered addresses, including randomized MAC addresses used to reduce tracking on Wi-Fi networks.
A MAC address is not the same as an IP address. MAC addresses are used for local network delivery, while IP addresses support routing between networks. Also, the term “physical address” can be misleading because software can change or randomize the value presented by a device.