In theory, every network card or network interface should have its own unique MAC address, different from every other network card or interface on the planet. If your computer has multiple network interfaces - say both a wired ethernet port and a wireless network adapter - each interface will have its own MAC address.
MAC addresses are unique - sort ofĪ Media Access Control (or MAC 1) address is a unique 48-bit number 2 assigned to every network interface. That limits the usefulness of MAC addresses for any kind of device location or tracing. While they do identify the device, when used in networking they travel only as far as the next device, like your router. MAC addresses are unique identifiers for each network interface on your device.