Optimistic concurrency control is a database management technique that allows multiple transactions to occur simultaneously without locking resources. It assumes that conflicts between transactions are rare, so it lets them proceed without immediate checks. At the end of each transaction, the system verifies if any conflicts occurred before committing the changes. If a conflict is detected, the transaction is rolled back, and the user may need to retry. This approach can improve performance in environments with low contention, as it reduces the overhead associated with locking mechanisms, making it suitable for applications with many read operations and fewer writes.