I.e. an abstract representation of a kind of project that can be instantiated into a concrete customised Maven 2 project.
An archetype knows which files will be part of the instantiated project and which properties to fill to properly customise the project.
Each archetype defines a set of common properties:
The minimal content of the jar file:
. |-- META-INF | `-- maven | `-- archetype-metadata.xml  `-- archetype-resources |-- ...  `-- pom.xml 
The common properties should be renamed to $target.groupId , ... to avoid name clash.