Exploring the pom plugin that does the modeling work and ran this command:
$ mvn help:describe -Dplugin=org.apache.cayenne.plugins:cayenne-maven-plugin
Notice that the cayenne:cdbgen and cayenne:cgen have identical text.
The key part of the response is:
This plugin has 3 goals:
cayenne:cdbgen
Description: Maven mojo to perform class generation from data map. This
class is a Maven adapter to DefaultClassGenerator class.
cayenne:cdbimport
Description: Maven mojo to reverse engineer datamap from DB.
cayenne:cgen
Description: Maven mojo to perform class generation from data map. This
class is an Maven adapter to DefaultClassGenerator class.
