Reality is the independent nature and existence of everything knowable, whether it is knowable by logical inference, empirical observation, or some other form of experience. Reality’s existence and nature are independent because reality does not depend on our mind’s apprehension of it to continue to exist or to maintain its character.
Consider Kant’s idea of the ‘thing in itself’: that aspect of existence always outside of our perceptions of it. In Kant’s view, we can never truly know reality in itself, what he called ‘the noumenal world’, because we are limited to our mind’s imposition of fixed ‘categories’ of knowledge upon our perceptions of it (this giving us what Kant called ‘phenomenal’ knowledge). So it would seem we are forever cut off from reality as it is in itself, that is, distinct from our minds’ apprehension of it.
Furthermore, Thomas Aquinas pointed out that our perceptions of the world around us cannot be knowledge, since perceptions can logically contradict each other. For example, I may say, “This chair is brown,” while another may say, “No, this chair is not brown, it’s white.” Since these perceptions contradict, perception cannot produce genuine knowledge, since truthful knowledge cannot contradict itself.
Therefore, genuine knowledge of reality would have to be direct knowledge of the object itself. And so reality itself, comprising the independent nature and existence of everything knowable, exists independently of our minds’ apprehension of it. At best, perceptions are not that which we know; rather, perceptions are that by which we know.
This whole subject has been debated and discussed since the formation of philosophical thought by many great minds. I suggest you make an attempt to understand the many differing schools of thought on the matter before claiming "I know the true nature of reality".