Multi-user database systems require concurrency control techniques in order to maintain data consistency and integrity while handling concurrent transactions. Four important concurrency control techniques are examined in this paper: timestamp-based, validation-based, lock-based (including the popular Two-Phase Locking (2PL) protocols). Lock-based protocols use locks to control access to shared resources; on the other hand, two-phase logic (2PL) guarantees transaction serialization. Timestamp-based protocols provide a consistent execution order by scheduling and ordering transactions according to distinct timestamps.Optimistic concurrency control, or validation-based protocols, validate transactions after they are executed in order to reduce conflicts without first obtaining locks. By means of an extensive investigation of various protocols, the principles, methods, benefits, and drawbacks are clarified, assisting in the well-informed choice and application of concurrency control techniques that are customized to meet particular database system needs.