These are project templates for camunda BPM platform, which enable a quickstart for developing process applications.
- Add archetype catalog (Preferences -> Maven -> Archetypes -> Add Remote Catalog): https://app.camunda.com/nexus/content/repositories/camunda-bpm/
- Create Maven project from archetype (File -> New -> Project... -> Maven -> Maven Project)
The complete documentation of the Maven Archetypes is provided as part of the camunda BPM User Guide.