Is created by a client and represents a single conversation, or session,
with that client.
Typically, persists only for the life of the conversation with the client.
In this sense, it can be likened to a pseudoconversational transaction.
If the bean developer chooses to save information beyond the life of a session,
he or she must implement persistence operations—for example, JDBC or
SQL calls—directly in the bean class methods.
Typically, performs operations on business data on behalf of the client,
such as accessing a database or performing calculations.
May or may not be transactional. If it's transactional, it can manage
its own Object Transaction Service (OTS) transactions, or use container-managed
OTS transactions. For an explanation of the relationship between OTS transactions
and CICS® units of work, see Enterprise beans—managing transactions.
Is not recoverable—if the EJB server crashes, it may be destroyed.