CascadeType Explained

PERSIST

maps to EnityManager.persist(). Make an instance managed and persistent.

MERGE

maps to EnityManager.merge(). Merge the state of the given entity into the current persistence context.

REMOVE

maps to EnityManager.remove(). Remove the entity instance.

REFRESH

maps to EnityManager.refresh(). Refresh the state of the instance from the database, overwriting changes made to the entity, if any.

ALL

all of the above

References

Java Persistence with Hibernate

Christian Bauer, Gavin King