Saying what reality is in isolation really does not get us anywhere, everything has meaning in context. So the context for Reality is the other aspects of Being which are Truth, Identity and Presence. It turns out that the other aspects give the grounding for formal systems, and their relations with each other give us the properties of formal system which are consistency, completeness and clarity (wellformedness). When we bring the formal system into contact with reality via testing then we get three more properties which are verifiability, validity, and coherence because those are the relations between reality and the other aspects related to the formal system. Reality is about testing. Via testing we verify and validate a given formal system in relation to reality. The best way of talking about this is that of Robert Rosen in Life itself where he shows that causality and logical connection are both forms of entailment and thus category theory is a good way to think about the connection of the formal system to the natural world.
So Reality is just one aspect which gains its own meaning by its difference between itself and the other aspects and though its relation to them based on the properties of formal system and their properties in relation to testing against nature.
It should also be mentioned that there are meta-levels of Being: Pure, Process, Hyper, Wild and Ultra and that all the aspects transform emergently at each of those meta-levels. Thus Reality is different depending on the meta-level you are approaching it on. And this is why reality is so hard to pin down. It participates in the higher logical type theory of Russell which defines different types at different meta-levels to resolve the paradoxes and absurdity of Being. The types at each meta-levels are the emergent transformations of the aspects of Being.