This begins the second and final of our “fundamental” chapters, and if you are not familiar with Enterprise JavaBeans (EJBs) at all, then definitely take a close look at this chapter. Because Seam applications rely almost exclusively on EJBs to provide the domain and business logic, this chapter is important in understanding how to implement a Seambased application. This chapter focuses almost exclusively on the Entity JavaBeans 3 specification (EJB3) but will touch on how to call EJBs from the client. The road map in Figure 4-1 shows where the focus of this chapter lies.