mvn install is the option that is most often used.
mvn package is seldom used, only if you're debugging some issue with the maven build process.
See: http://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html
Note that mvn package will only create a jar file.
mvn install will do that and install the jar (and class etc.) files in the proper places if other code depends on those jars.
I usually do a mvn clean install; this deletes the target directory and recreates all jars in that location.
The clean helps with unneeded or removed stuff that can sometimes get in the way.
Rather then debug (some of the time) just start fresh all of the time.