What does ACID stand for?

ACID stands for Atomicity, Consistency, Isolation, and Durability, which are key properties that ensure reliable processing of database transactions.

• Atomicity guarantees that a transaction is treated as a single unit, meaning that it either completes fully or not at all. This prevents half-finished transactions that could lead to data inconsistencies.

• Consistency ensures that a transaction moves the database from one valid state to another, maintaining database invariants and rules throughout its execution.

• Isolation protects transactions from interference when they are executed concurrently. This means the operations of a transaction do not affect each other until the changes are committed, ensuring that transactions do not see intermediate states of others.

• Durability guarantees that once a transaction is committed, it will remain so, even in the event of a system failure. This means the results of a transaction are permanent and are saved to non-volatile storage.

These principles are fundamental for maintaining data integrity and reliability in database systems, making the option referencing these four characteristics accurate. Other options do not correspond to established concepts in database management, with terms that either don't match (like "Concurrency" and "Control") or deviate away from standard definitions in the context of database transactions.