A very elementary question:
When we speak of adding a name to a router or a switch, what do we mean by that?
Thank you very much.
I'll take it that you're talking about giving the device a hostname
There are no technical requirement to "name" a device. But as the name is often used to (depending on manufacturer/line)
It's normally a good idea do name your device.
Depending on the particular device, there are variation on the method.
The device will now refer to itself by "name-of-device" instead of a generic name (ie: router, switch, etc) in prompts, syslogs, CDP/LLDP, etc... This is nothing much more than if you entered a computer name in your PC's windows setup.
A side effect of that is that it's wayyy more fun to refer to your router/switch name than it's IP and/or function
Instead of saying that the Core Switch has blown, you can say "insert-device-name-here died". another game often played is to name all your devices following a family/category of name. I've seen servers named after fighter planes (hornet, falcon, etc) named after LoTR character names, etc.
It's more satisfying to say that "MinasTirith (your firewall's name) is secure" than "FW-ASA-1000-BSMT-1 is secure".