JPA EntityManager: Why use persist() over merge()?

Question

EntityManager.merge() can insert new objects and update existing ones.

Why would one want to use persist() (which can only create new objec

Answer 1

persist(entity) should be used with totally new entities, to add them to DB (if entity already exists in DB there will be EntityExistsException throw).

merge(entity) should be used, to put entity back to persistence context if the entity was detached and was changed.

Probably persist is generating INSERT sql statement and merge UPDATE sql statement (but i'm not sure).