(via maven.apache.org)
Maven 2.0 is based around the central concept of a build lifecycle. What this means is that the process for building and distributing a particular artifact (project) is clearly defined.
This means that it is only necessary to learn a small set of commands to build any Maven project, and the POM will ensure they get the results they desired.
There are three built-in build lifecycles: default, clean and site. The default lifecycle handles your project deployment, the clean lifecycle handles project cleaning, while the site lifecycle handles the creation of your projects site documentation.