An EJB module contains one or more Enterprise Java Beans (EJB). An EJB consists of
the following classes:
bean implementation
remote interface
home interface
primary key (for entity EJBs)
In addition, an EJB module can contain:
other helper classes
resources that are referenced (by name) by the classes that comprise the EJB
The components in an EJB module are archived into a JAR file. In addition, an EJB
JAR module contains ejb-jar.xml files in the
\META-INF directory at
the root EJB module directory. The XML files represent the component-level
for the module. The archive may contain other XML files depending upon
your declaration of deployment descriptor parameters.