MAC addresses are just one of the basic components of Ethernet networks, but even though they serve a low level function, they are important for the internet’s local network to work. MAC addresses are needed for a device to connect with and communicate with a machine on this local level. They only work on this physical local network level though, often called a LAN. This is different from how an IP address works because they can cover the whole internet. Routers use these to figure out where to direct data, even across several different areas or connections. These don’t really affect your physical connection though, which is where the MAC address takes over. So these two different addresses have to work together to help you access the world of the internet from your personal location.