Seperates tends to mean anything that wasn’t actually sold as a single purchased unit.
Seeing as you know how live music sounds, I’d suggest you find a place where you can demo some decent kit, new or secondhand, and have a listen. The differences can be very subtle or utterly unmissable, but you should be able to figure out what you like 🙂
We’ll rustle up some suggestions, I’m sure.
Meanwhile, I think you could do with some background research, and an introduction to key technologies etc.
Maybe start by reading some overviews published by What HiFi, and if you can find any articles of interest published by HiFi World (UK) they’re usually really knowledgeable (but are less often aimed at n00bs).
In your case, your knowledgeable ears give you an advantage!