Sure. Though I’m not an expert on mDNS or anything. It stands for multi cast DNS. In a normal scenario, when your PC tries to connect to a local resource at its hostname it will use a local DNS server (or its own cache). It’s like a phone book. I know who I’m looking for, I just need to look in the phone book and see what their IP is. With mDNS there is no server. You’ll have a service that will plan to respond at a particular .local hostname, so like jellyfin.local (this is just an example, I don’t know if it has mDNS) but that isn’t registered on a server. Instead when your PC wants to reach jellyfin it will send a multi-cast to the other local devices and say “ok, I’m looking for some guy named jellyfin.local, which one of y’all is that?” And the jellyfin server will respond and say “yo what up, this is my ip address”

So anyway, that only works with .local addresses. You could use .local with a regular dns server, but then you may run into a conflict. So that would be the benefit of reserving .internal