JPA is an API, provided by Oracle.
Hibernate, EclipseLink etc. are implementations of that API.
These annotations should be red as following:
class wood @OneToMany @JoinColumn(name="wood") Set<Tree> tree | Object wood. Property tree. One wood has many trees. Property has to be a collection |
class tree @ManyToOne @JoinColumn(name="tree") Wood wood | Object tree. Property wood. Many trees in wood. |