Groups are characters which have banded together under a leader and co-leader. The groups menu can be accessed anywhere at any time, and groups have no cap on the number of members. There are different group types with their own purposes, but generally groups are for characters who are either on their own without town allegiance, or are rebelling against a town. For more details, click the wiki link above.
Closed Beta Prep (Scheduled: 5/04): This is a closed testing session available to race founders.