Windows Live Groups(The web service where users can share their thoughts, photographs, and interests with all members of a group. Members all contribute to a group profile, and can post blog entries, photos, and other items, just as they can to an individual profile)
SharePoint group(A group of users that can be created on a SharePoint site to manage permissions to the site and to provide an e-mail distribution list for site users. A group can be used by many sites in one site collection)
