Pralaya, or laya, (Sanskrit, "dissolution") is a term in Hindu comprehension that conveys all appearance is subject dissolution, but not to destruction, because dissolution leads to recreation.
The term is especially used at the ending of a kalpa (cosmic cycle), which then via pravrtti leads to a new creation. But there may be also lesser pralayas such as the great flood of Manu (See Mahabharata, Vana-prana 1. 8. 1. 1-10), which occurred when all creation was submerged under a deluge. However, Manu had rescued a fish that grew large, and told him to build a large boat in which he was to take seeds and animals. Then the fish rowed the boat to safety by anchoring it to the top of the highest Himalayas.