What is Reality?

I was thinking the other day that most people have no idea what reality is. Why not? because they don't understand what "not reality" is. I thought for a while what "not reality" meant to me and came to a conclusion. I believe that being able to tell the difference between reality and "not reality" is to be able to tell the realize that our perceptions/senses are in fact unrelated to what is real and what is not. Most of the time i assume that all my surroundings, the things i see/hear/feel/etc. are in fact there. In fact I do this subconsciously, i don't think about how everything around me is real but i just "go with the flow". However there are times when i realize that the things around me may or may not be real, for various reasons. No I'm not talking about hallucinations, delusions, or imaginary things but rather an understanding that there is no way to prove that anything i perceive is in fact real.