As I mentioned, every device on a network must be uniquely identifiable so that, at any given time, requests intended for a specific device can be delivered. Likewise, unique addressing means that any responses can be reliably returned to the originating device, no matter how many network nodes lie between the two. If someone has written a service that solves a problem you have, it's only useful to you if you can actually use that service. This means either knowing the address of the device hosting that service, or, at the very least, knowing who to ask for the address.
Thankfully, this is a problem that was solved long before even the earliest incarnations of the modern internet. I am, of course, referring to ...
