Can you explain the ACID principle in the context of working with databases?

The ACID principle describes the properties of transactions in databases that ensure data reliability and integrity:

• Atomicity — a transaction is completed in full or not at all. If one part of the operation fails, all changes are rolled back.
• Consistency — after a transaction completes, the database remains in a correct state, satisfying all rules and constraints.
• Isolation — parallel transactions do not affect each other, resulting as if they were executed sequentially.
• Durability — after a transaction is committed, changes are saved in the database even in case of failures.

For example, when transferring money between accounts:

• Deducting from one account and crediting another is one transaction.
• If the deduction succeeds but the credit does not, the transaction is rolled back (atomicity).
• Account balances always remain correct (consistency).
• Other operations do not see intermediate states (isolation).
• After confirmation, changes are permanently saved (durability).