system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why are IPv4/IPv6/NetBIOS addresses and names needed in networking when every device has a unique MAC address?
gpt
The MAC address does not give any description of where the device is located or how you can send a packet to it. If we were all just using MAC addresses for all traffic then every router at every ISP needs a list of all the devices in the world and where to find them. This would be extremely difficult to maintain. The current system of addresses is based on the geographical and logical location in the network. A router only needs to look at the first bits of an address in order to know where it should send the package next.

You can compare it to a post address. We technically do not need to write the street name, post code and country on every letter we send in the mail since most people have a unique name. However it is very helpful to the post office to know if the receiver is living on the other side of the city or in the next country. The way we have it now they can only look at the post code and sort it into rough boxes that can be sent in different directions. A post office in New York City does not need to know your street address in Los Angles and only need to know what post code range is used for the west coast cities.