A Pralaya specifies different periods of time during which a non-activity situation persists, as per different formats or contexts. The word Mahapralaya stands for "Great Dissolution". During each pralaya, the lower ten realms (loka) are destroyed, while the higher four realms called Satya-loka, Tapa-loka, Jana-loka, and Mahar-loka are preserved. During each Mahapralaya, all 14 realms are destroyed.
In the Samkhya philosophy, one of the six schools of classical Indian philosophy, pralaya means "non-existence", a state of matter achieved when the three gunas (principles of matter) are in perfect balance. The word pralaya comes from Sanskrit meaning "dissolution" or by extension "reabsorption, destruction, annihilation or death".