I think things and people from the spirit world and realms that people in the universe where Goku came from have as part of their universe use different kinds of spiritual energy that is different from Ki energy and that there is a high variation of that spiritual energy and it’s similar to God Energy that they describe when they deal with Beerus and transformations such as Super Saiyan God,
I think they describe the spiritual energy that Beerus uses as Destruction Energy which would be a form of spiritual energy,
to describe how their spirit world and spirit realms work you could describe them as spiritual dimensions that have a ‘materialization’ in locations different from the location of the living world but still with a direct connection to them,
some spiritual worlds could be understood similar to The Force from Star Wars as dimensions existing with and alongside the living world with materialization being the same as the living world almost like a physical world overlayed with a spiritual world that has things that sort of materialize from one into the other, Spiritual worlds like that could exist but have not been explored so far within many of the universes similar to theirs,
I like to use the word ‘realm’ to describe the spirit world that has a ‘materialization’ or location different from the living world yet with a connection to the living world and that a spiritual world like a realm could exist along with a spiritual world overlayed over/with the living/physical world, potentially their different universes could have different overlayed spiritual worlds as well,
so there might be many other spirit realms also that are unique to themselves that could have people like Garlic and Garlic Jr. and the type of being he is as well as spirit realms like where Demon King Debura comes from,
some of them might not even be aware of each other and when realms or people from realms like that go from one realm to another it would be a big deal and all of the realms that would be spirit realms of their universe would be identifiable as their universe as all of them have the same connection to, yet in different ways, to their physical/living world,
Universe is a term probably used by people within their universe when referring to their own universe to refer to their total physical/living world as they understand it even though from an outside perspective it could be used to describe the totality of their physical and spiritual world/worlds and their distinguishable interrelations and still be used accurately when referring to other universes,
the connection to the other universes would be understood as being a part of their Universe and others while still allowing for the separation between them to be distinguishable as universes,
I think many from their Universe would think that understanding is exciting as they could find people more powerful than they previously thought possible and in different ways than they thought possible and they would be excited that they could potentially train with them to better themselves,