Pragmatically speaking that which we have come to know via science. Is there more to it outside of science that we will perhaps never know? Quite possibly.
There are all the electrons, quarks, etc. etc. but the universe is made of all the experience of all those points of light and dark. Each one represents a universe on its own and can be the whole or part of the perceived universe.
Energy, matter and in our world, water. The tangible and the intangible. Things we can see: like people, plants and stars; and things we can't see, like electricity, money and gravity.