From Second Life Wiki
What are groups?
Groups are organizations you can join and belong to in Second Life®. Group members have certain special privileges:
- Group members and officers get special titles. When you have a group active, your title appears above your name.
- Groups have a joint Linden dollar balance. Any Linden dollars paid to the group are paid out evenly to all group members each day.
- Groups can jointly own land, with each member making a contribution to help pay for the land's cost.
- You can give certain special permissions to group members only. A group member might restrict land access to group members only, or script an object that has special functions only group members can activate.