ACID Properties and How MySQL Satisfies Isolation

Question: What is ACID (Atomicity, Consistency, Isolation, Durability), and specifically how does MySQL satisfy the Isolation property?

Answer outline: Atomicity ensures a transaction either fully commits or fully rolls back. Consistency ensures a transaction moves the DB from one valid state to another. Isolation ensures concurrent transactions don't interfere with each other's intermediate state. Durability ensures committed changes survive crashes. MySQL (InnoDB) satisfies Isolation via configurable isolation levels (Read Uncommitted, Read Committed, Repeatable Read [default], Serializable), implemented using MVCC (Multi-Version Concurrency Control) with undo logs to give each transaction a consistent snapshot, plus row-level locking to prevent conflicting writes.