Quite literally, yes. The branch of magic is called Dunamancy and it is more specifically the manipulation of what we call dunamis, in my world. Dunamis is the energy that quite literally shapes the multiverse and holds it together, something like an invisible web of tethers. We tap into that and bend time or shape gravity. But, to answer your second question, it's quite literally potentiality, being able to peer into other possible timelines and pull from them or shift fate into one's favor--or another's disservice.
I've found limitations here, as I think most have in one way or another in regards to their regular abilities; there is just some magic that Vallo seems to want to keep to itself.