The name of a resource indicates what we seek, an address indicates where it is, and a route tells us how to get there.
You might wonder when that document was written… it’s from January 1978. They got it absolutely right 42 years ago, and we completely messed it up in the meantime with the crazy ideas of making IP addresses resource identifiers.
Imagine that you’d be identified by the street address at which you were born and had to carry that address around (and update Google Maps) every time you decided to travel. How crazy is that… and yet that’s precisely how some application developers love to think of the world our servers live in, and what virtualization vendors managed to persuade sysadmins makes perfect sense. No wonder networking is as complex as it can get before collapsing in a smoldering pile of kludges.
For more details, watch the Introduction to Network Addressing videos.