Concurrency control in database management systems (DBMS) refers to the process of managing multiple transactions accessing and modifying data simultaneously without interfering with each other.

In a multi-user environment, where multiple users are accessing the same database at the same time, it is crucial to ensure that data integrity is maintained and that transactions are executed correctly. Concurrency control mechanisms are put in place to prevent issues such as lost updates, dirty reads, and inconsistent data.

These mechanisms ensure that transactions are executed in a way that maintains the consistency and integrity of the database.

One common approach to concurrency control is the use of locks, which prevent other transactions from accessing data that is being modified by another transaction.

This helps to prevent conflicts and ensures that transactions are executed in a serializable manner. Another approach to concurrency control is the use of timestamps or versioning, where each transaction is assigned a unique timestamp or version number.

This allows the DBMS to track the order in which transactions are executed and resolve conflicts based on timestamps or versions. Overall, concurrency control is essential in ensuring that database transactions are executed correctly and that data integrity is maintained in a multi-user environment.

By managing the access and modification of data by multiple transactions, concurrency control helps to prevent data corruption and ensure the reliability of the database system.