Entity bean represents the persistent data stored in the database. It is a server-side component.
In EJB 2.x, there was two types of entity beans: bean managed persistence (BMP) and container managed persistence (CMP).
Since EJB 3.x, it is deprecated and replaced by JPA (Java Persistence API) that is covered in the hibernate tutorial.
In hibernate tutorial, there are given hibernate with annotation examples where we are using JPA annotations. The JPA with Hibernate is widely used today.