LaToyaBurdiss it is just an organizational tool. It depends which you prefer. I feel like if you have a selection of related notes that doesn’t change often, use a hub. If you are adding new related notes often use a collection (Smart Folder).
For example, I use a Projects Hub but a Resources Collection. I’m usually working on a few projects at a given time, and they last for awhile. But resources get updated often, and listing all of them would be exhausting.
I have a Friends and Family Hub but a People Collection, since I’m sometimes adding contacts that my come and go, but my friends and family is more stable.
Here’s the thing: use whichever makes sense to you. Both work equally well. The whole point is to keep track of the note in a way works for your brain.