What types of relationships between entities are implemented in Hibernate?

Hibernate implements the following types of relationships between entities:

• One-to-One — one entity is related to one other entity.
• One-to-Many — one entity is related to many other entities.
• Many-to-One — many entities are related to one entity (inverse of One-to-Many).
• Many-to-Many — many entities are related to many other entities.

Each of these relationships can be configured using annotations such as @OneToOne, @OneToMany, @ManyToOne, @ManyToMany, as well as specifying cascade operations and fetch strategies. For example:

@Entity
public class User {
    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private Set<Order> orders;
}

@Entity
public class Order {
    @ManyToOne
    @JoinColumn(name = "user_id")
    private User user;
}