Rta is closely associated with the gods Varuna and Mitra, who are the deities in charge of cosmic order. The term is almost certainly pre-Vedic in origin. Evidence of this is that it is rarely used in later times or in conjunction with any other Vedic gods. Also, it is not considered to be a god itself, which is out of character for the Aryan writers of the Vedas, who tended to anthropomorphize everything.
Rta is a term which signifies the cosmic order of the universe. It is through rta that the sun rises and sets, that rivers flow, trees grow, and animals are born. It is the twelve-spoked wheel of the cyclical year. It is seen as the path one follows to a goal. A just and honorable man will always try to uphold rta. It is always advisable to act in accordance with rta, for then things will invariably go smoothly. Rta is therefore also seen as Truth.