Maven build lifecycle

How long can you use Maven without understanding the Maven build lifecycle?  Notes from Introduction to the Build Lifecycle for someone who has already used Maven for awhile:

• Three built-in lifecycles: default, clean and site
• Different build phases for each lifecycle
• A goal represents a specific task, may be bound to zero or more build phases. A goal not bound to any build phase could be executed outside of the build lifecycle by direct invocation
• goal = Ant task (roughly) = an action during the build
• There is both a clean lifecycle and a clean phase 
• If a build phase has no goals bound to it, that build phase will not execute
• Each packaging (e.g. jar, war, etc.) contains a list of goals to bind to a particular phase
• Plugins can provide/offer multiple goals for execution
• If more than one goal is bound to a particular phase, the order used is that those from the packaging are executed first, followed by those configured in the POM

Can't add web project to Tomcat in STS

Trying to add a web project to a Tomcat instance.  The project has the Dynamic Web Module project facet enabled (Properties > Project Facets).  Still get this message:

Reason:

Grails project facet is not supported.  Need to use tc Server within STS.