Since God’s original work of creation of the physical realm, which brought into being what had not previously existed, he has continued to work out his purposes in what he created. (This is contrary to some people’s idea that God wound up the universe like a clock and left it to run by itself.) This active working can be designated as continuing creation, providence, and miracles. Though this is more for our own thinking than something we are obliged to believe or necessarily as the Trinity thinks of it.
Continuing creation is God using things that do exist to create new things. For example, God uses two cells from our parents to create us who had no previous physical being, although we did receive the ancestry contained in our parent’s genetics.
In providence God uses what exists and shapes matter, energy and events in accordance with the way he has created them to accomplish his purposes.
Miracles involve actions we do not understand. Many people believe miracles are impossible as they seemingly require the violation of natural laws. However, we can think that if God intended miracles he would create a universe that could be used in ways that are beyond the usual. For instance, I do not believe that when Jesus started doing miracles he surprised anybody in heaven (only people on earth). It was just part of God’s original plan.