Can you explain what is meant by consistency in the context of ACID transactions?

Consistency within ACID transactions means that after a transaction is executed, the database transitions from one correct state to another, adhering to all specified rules and constraints (such as data integrity, foreign key constraints, etc.).

If a transaction violates these rules, it is rolled back, and the database remains in its previous consistent state.

Example: when transferring money between accounts, the sum on both accounts should remain correct — if money is deducted from one, it should be added to the other. If something goes wrong, changes are not applied to avoid violating consistency.