What are the main rules that determine the behavior of transactions in database systems?

The fundamental rules that define the behavior of transactions in database systems are described by the ACID properties:

• Atomicity: a transaction is executed completely or not at all.
• Consistency: after a transaction completes, the database remains in a correct state.
• Isolation: concurrent transactions do not affect each other as if they were executed sequentially.
• Durability: after a transaction is committed, the changes are saved even in case of failures.

These rules ensure reliability and predictability in data handling in multi-user systems.