Defining SPS Profiles
User profiles in SharePoint help track the interests and expertise of your knowledge workers. In an external portal, profiles are not usually shown to other users, and they are chiefly of interest to site administrators. In the enterprise portal, on the other hand, profiles contain interesting information and can be valuable to users as well, who can use the profiles as a means of connecting to people with similar interests.
As an administrator, you can create user profiles for other members of your online community. You control the properties for profiles and the access granted to property profiles for various groups of users. For instance, users can have private and public property values in the same profile.