ACID

ACID is a set of principles that ensure reliable processing of transactions in a database. "Atomic" means transactions are all-or-nothing, so if one part fails, none of it is applied. "Consistent" ensures data remains accurate and follows rules after a transaction. "Isolation" means transactions don't interfere with each other, maintaining integrity during simultaneous operations. "Durability" guarantees that once a transaction is completed, its results are permanent and survive system failures. Together, ACID principles help databases operate reliably, accurately, and securely, even in complex or concurrent environments.