A Pralaya (Sanskrit: प्रलय "downfall, destruction") or world night is that intermediate state during which an evolving world system completely withdraws from external spatial revelation, the so-called Manvantara or world day, into a purely spiritual existence.
Our planetary system undergoes seven embodiments in the course of its evolution, which are called the so-called 7 Occult Planets, and between each of these outer embodiments lies a great Pralaya. Our present planetary system, to which our Earth also belongs, is the fourth and middle of these outer re-embodiments.
Each one of the occult planets in turn evolves in a succession of seven life stages or rounds. Between each round is a small Pralaya.