1.Atomicity : A transaction should be all or nothing.If it fails to complete, the database will be left as if none of operations had ever been performed — known as rollback.

2.Consistency: A transaction should be incapable of breaking any rules defined for database.For example, foreign key must be obeyed.If for some reason this is impossible, the transaction will be rollback.

3.Isolation: The effects of the transaction will be completely invisible to all another transactions until it has completed successfully.This guarantees that the transaction will always see the data in a sensible state.

4.Durability: The data should retained intact. If the system fails for any reason, it should be always be possible to retrieve the database up to the moment of failure.

from Pro Hibernate Book.