# Difference between an IP and MAC address

For any packet we attach the source and destination Internet Protocol (IPv4) . This packet may need to travel through many different networks . For each different network it will get a new layer 2 header with the MAC address of the router it entered the network on and the router it needs to leave the network on.

MAC address are really only there for a single network hop whereas the Internet Protocol (IPv4) is there for the whole journey.