Every piece of hardware on a network has a unique MAC address. This is embedded in the hardware when the product is made in the factory, and the user cannot change it. On a computer, the MAC address is a unique code built into a NIC. No two computers have the same MAC address. A MAC address is made up of 48 bits of data, usually written as 12 hexadecimal characters.
NICs enable desktop and laptop computers to connect to a network. NICs are small circuit boards that connect to the motherboard. Smartphones also use a GSM chip to connect to the telephone network. Games consoles contain a NIC card so users can access the internet, download games and play online.