Getting Started with ADF - Oracle ADF 11gR2 Development Beginner's Guide - page 41

EmpVO.xml : This is a view object based on EmpEO that is used to manipulate the
Employee table through the enity object.
The EmpVO.xml file will have the data that was retrieved from the data source
using the SQL query. The query secion will display the query for the view object
as shown in the following screenshot:
EmpDirectoryModule.xml : This is the applicaion module that we have created
through the view object to accomplish the create, update, and remove operaions
for a record in the Employee table.
The Data Model secion of the EmpDirectoryModule.xml file will show the usage
of the EmpVO view object.
The bc4j.xcfg file will have the metadata information about the
database connection used by the application module. This file also
defines the runtime parameters configured for the application module.