The Session bean and Entity bean are two main parts of EJB container.

Session Bean

--represents a workflow on behalf of a client

--one-to-one logical mapping to a client.

--created and destroyed by a client

--not permanent objects

--lives its EJB container(generally) does not survive system shut down

--two types: stateless and stateful beans

Entity Bean

--represents persistent data and behavior of this data

--can be shared among multiple clients

--persists across multiple invocations

--findable permanent objects

--outlives its EJB container, survives system shutdown

--two types: container managed persistence(CMP) and bean managed persistence(BMP)