maven inheritence, aggregator project

Aggregation

<project ..>
  <...>
  <modules>
    <module>my-project</module>
    <module>another-project</module>
  </modules>
</project>

Inhertence

<project ...><br />  <...><br />  <parent><br />    <groupId>org.codehaus.mojo</groupId><br />    <artifactId>my-parent</artifactId><br />    <version>2.0</version><br />    <relativePath>../my-parent</relativePath><br />  </parent><br /><br />  <artifactId>my-project</artifactId><br /></project><br />

A POM project may be inherited from - but does not necessarily have - any modules that it aggregates. Conversely, a POM project may aggregate projects that do not inherit from it.