What is software architecture of EJB?

Session and Entity EJBs consist of 4 and 5 parts respetively:

1. A remote interface (a client interacts with it),

2. A home interface (used for creating objects and for declaring business methods),

3. A bean object (an object, which actually performs business logic and EJB-specific operations).

4. A deployment descriptor (an XML file containing all information required for maintaining the EJB) or a set of deployment descriptors (if you are using some container-specific features).

5.A Primary Key class - is only Entity bean specific.