The word illusion is from the Latin illusio, which means “the action of mocking”. Illusion is defined as the action of deceiving, the state or fact of being intellectually deceived or misled or the perception of something objectively existing in such a way as to cause misinterpretation of its actual nature. Deceit is the core present in all Illusion.
Reality on the other hand is defined as the quality or state of being real; a real event, entity or state of affairs; something that is neither derivative nor dependent but exists necessarily in actual fact. Truth is the core present in reality.