What does the C in ACID-compliant stand for?

In the context of ACID compliance, which is essential for database transaction management, the 'C' stands for Consistency. This principle ensures that any transaction will bring the database from one valid state to another valid state without violating any database rules, including integrity constraints. When a database is consistent, all data must be valid according to defined rules (like foreign keys, unique constraints, etc.) before and after the transaction is executed.

The concept of consistency is critical in maintaining the accuracy and reliability of data, particularly in systems where multiple transactions are occurring simultaneously. If a system does not enforce consistency, it could lead to data corruption or anomalies, undermining the integrity of the database as a whole. This foundational element of ACID properties helps ensure that all transactions happen as intended and that any partial transactions can be rolled back, thus preserving data integrity.