Seing as there is already a Reality page which people seem to mostly agree with and seing that I have a different take on it, instead of trying to edit said page I'm putting my attempt at defining it here as a blog post.
"Reality is that which, when you stop believing in it, doesn't go away" Philip K. Dick
Reality is where we, the writers of this wiki, as well as the reader, live. We are all part of reality in whatever way we exist.
Reality is whatever is real. It means the state of being real, the state of things as they actually exist as opposed by how we think or believe they exist. Reality is all that exists, no matter what is imagined, believed, perceived or even believed to be known about it. Even if all we think we know about it is wrong, reality is the truth, not what we think or believe. Even if reality where completely unknowable, its mysterious truth would still be what reality is.
Reality does not care about what we think it is. It is what it is no matter what. Unless in the extremely unlikely case that reality actually is subjective, therefore being defined by our opinions of it. If that is the case then reality truly is whatever we imagine or believe it to be and nothing more. It is possible that reality as a whole or in part is unthinkable or unimaginable by us. It would also be possible for it to be paradoxical in nature and to not follow the laws of logic despite what it looks like. Actually it could be outside or beyond any sets of laws we have determined through observation and reasoning. Both the observations or the reasoning could be flawed or reality could just be strange enough to encompass both possibilities.
Reality possesses a Cosmology. That is to say, it possesses an organizational structure of some kind. Both through science and religion we have tried to find out more and more about that structure of reality. About how it is organized, what it is made of, etc. The current accepted belief of reality is that it is composed by a Universe (possibly more than one as some theorize and believe) which contains three spatial dimensions and a temporal one forming a four dimensional space-time fabric. But there is always the chance that all that we think we know is completely wrong and reality is something else entirely. We could be completely unable to perceive it as it truly is. But it is a safe assumption that what we experience rightly corresponds to the true reality, at least partially. Even if we are unable to perceive its ultimate true nature, our senses and what we perceive through them are necessarily part of reality as well.
Reality doesn't necessarily mean "material" only or at all although that very strongly appears to be, at least, part of it. If spirits exist, if there is some kind of spiritual realm, those are part of reality as well. Whatever emotions one feels, whatever thoughts one has, whatever one imagines, all those things are part of reality at some level, probably a non-material one. And that part of reality at least seems to truly be subjective to some extent.
What it is
If we where living inside a simulation, that would be the reality. The simulation would be real, much like the software used on this wiki is real, therefore part of reality. And so would any higher part of reality where such simulation would be running. Probably some computer in some external world. If someone believes that all reality exists only in their mind, all fruit of their imagination, than that would still be reality. Reality would be them plus their own imagination and anything else not them that would also exist if anything. If reality is only some kind of projection or illusion imposed on us by some higher intelligences, well, that illusion is still part of the reality, as are those intelligences and the place where they live. These hypothesis are presented only to show that, no matter what it is, by definition reality is real. It is one of those obvious self-sufficient truths. An axiom without which nothing else can be reasoned.
Creator God Hypothesis
If it is true, like many believe it to be, that reality has a creator god of some kind than it would also be part of reality in some way. If it is considered to be "outside" of reality, that just means that the true definition of reality would be the set containing two elements: the creator god and reality. Either it created itself along with reality meaning that the reality set came from nothing or it had no start, therefore neither did the reality set, for before it contained reality, it already contained the creator god. Other possibilities are for the creator god to exist without existing, therefore reality would have been created by a non-existing entity or for the creator god to be a part of reality itself, therefore part of reality created the whole of it.
The definition presented on the current Reality page seems to better refer to a concept of observable reality instead of the full reality while the mention on that page to "areas outside of reality" and "another form of reality" would better refer to non-observable parts of reality. Obviously as analogous concepts to those of observable universe vs the whole universe. It is not important to differentiate between the case of those parts being non-observable in their essence vs them being non-observable for the time being due to our limitations.