Definition: An isolation level defines how much one database transaction is protected from changes made by other concurrent transactions.
Common levels include Read Uncommitted, Read Committed, Repeatable Read, and Serializable.
Examples:
- Read Committed: You don’t read another transaction’s uncommitted changes.
- Repeatable Read: Reading the same row twice within a transaction gives a stable result.
- Serializable: Concurrent transactions behave as if they were executed one after another.