Groups in BuddyPress are a gathering of members, blog posts, photos and any other user generated content.
Any member can create a group in BuddyPress. They then become the group administrator which means they are given the option to approve or reject members wanting to join the group. They are also given the task of approving, rejecting or marking as spam content that other members tag to the group.
Every member can write blog posts and upload images to their own profile. Instead of specifically uploading content into a group, members can tag their content with a unique group tag (each group is given a unique tag once created). Once it has been tagged with the group tag, it will be placed in the approval list for the group admin to either accept or reject. Once it is accepted it will appear on the group overview page.
Quick links will likely be added to content upload pages for group tags, so that the user doesn’t have to remember them.
There is also the potential for each group to have its own BBPress forum for group related discussions