Correspondence Theory Of Truth
According to the correspondence theory of truth, reality is whatever corresponds with this world's existence. Anything that makes sense in the context of the universe's reality is true, and anything that does not correspond is false. The reason that particular belief is true is that it corresponds to those facts that the world is offering.
For example, the belief that the color of the sea is blue and the color of the sky is also blue is along with the idea that the sky and sea are blue because that the person believes to be true. Another example is that the bird is flying. This corresponds to the fact that the bird is flying.