Media Access Control (MAC) addresses are talked about in various sections on the site, such as the OSI-Layer 2, Multicast, Broadcast and Unicast. We are going to analyse them in depth here so we can get a firm understanding of them since they are part of the fundamentals of networking.
MAC addresses are physical addresses, unlike IP addresses which are logical addresses. Logical addresses require you to load special drivers and protocols in order to be able to configure your network card/computer with an IP Address, whereas a MAC address doesn't require any drivers whatsoever. The reason for this is that the MAC address is actually "burnt-in" into your network card's memory chipset.
The Reason for MAC
Each computer on a network needs to be identified in some way. If you're thinking of IP addresses, then you're correct to some extent, because an IP address does identify one unique machine on a network, but that is not enough.