You can deploy applications or individual modules that are independent of applications; see About Modules and About Applications. Individual module-based deployment is preferable when components need to be accessed by:
Other modules
Java EE applications
Application clients (Module-based deployment allows shared access to a bean from an application client, a servlet, or an EJB component.)
Modules can be combined into an EAR file and then deployed as a single module. This is similar to deploying the modules of the EAR independently.