Tell us about the lifecycle of an entity in Hibernate (entity states)

In Hibernate, the entity lifecycle passes through several main states:

1. Transient — the object is created in memory but not associated with a Hibernate session and not saved to the database.
2. Persistent — the object is associated with a Hibernate session and is being tracked; changes are automatically synchronized with the database upon commit.
3. Detached — the object was associated with a session, but the session is closed or the object is detached; changes will not be automatically saved.
4. Removed — the object is marked for deletion from the database upon the next commit.

Example transitions:

Session session = sessionFactory.openSession();
Entity entity = new Entity(); // transient
session.save(entity); // persistent
session.close();
// entity is now detached

Thus, managing entity states is important for correct data handling and optimizing database interactions.