Maven profiles are a pretty neat concept for organizing different settings for different builds.

Typically one sets them up in your settings.xml.  Projects will also have profiles in profiles.xml whose values you can override with your values in settings.xml.

A few observations I made about profiles.

1. Your profile is the conglomeration of all your active profiles in your settings.xml.
2. To activate other profile during a single maven execution, mvn -P profile1, profile2.