Explain the concept of isolation in ACID transactions and its role in ensuring data integrity.

Isolation in ACID transactions means that parallel transactions should not affect each other, i.e., each transaction should execute as if it were the only one in the system.

The role of isolation in ensuring data integrity:

• Prevents "dirty reads," where one transaction reads uncommitted data from another.
• Avoids non-repeatable reads, where data changes between two reads by different transactions.
• Protects against phantom reads, where new rows appear or disappear as a result of another transaction.

Isolation levels (e.g., Read Uncommitted, Read Committed, Repeatable Read, Serializable) allow balancing between performance and strict isolation.

Example: if two transactions try to modify the same account simultaneously, isolation guarantees that the final balance will be correct and updates will not be lost.

Thus, isolation ensures data consistency and reliability during concurrent database operations.