Reality is the state of things as they actually exist, rather than as they may appear or might be imagined. In a wider definition, reality includes everything that is and has been, whether or not it is observable or comprehensible.
Reality is often contrasted with what is imaginary, delusional, (only) in the mind, dreams, what is false, what is fictional, or what is abstract. At the same time, what is abstract plays a role both in everyday life
I believe the Forms which Plato believed in were not real. He claims that what we see on earth are mimics of the real thing, only with a lot of imperfections. In his Allegory of the Cave, outlined in The Republic, he called mimics artificial replicas of the real thing. In real life all that is seen is an illusion (smoke) of the real thing.