What is a transaction in the context of working with databases?

A transaction in database management is a sequence of operations that are executed as a single unit. It either completes successfully (commit) or is entirely rolled back if an error occurs.

The main properties of transactions (ACID):

• Atomicity: all operations within a transaction are either fully completed or not executed at all.
• Consistency: a transaction transitions the database from one valid state to another.
• Isolation: concurrent transactions do not affect each other.
• Durability: after a transaction is committed, the changes are saved even in case of failures.

Example: when transferring money between accounts, the debit and credit operations should be in one transaction to prevent data inconsistency.

Transactions help manage concurrent access and ensure data integrity.