Assign profile realms to your sites if you need to separate groups of external users who will access those sites or to maintain different profile information for individual users on your sites. See more information in Profile Realms and Working with Profile Realms.

You can associate a site with only one profile realm. If multiple sites are part of a sharing group and they share data, all of the sites in the group must be associated with the same profile realm. See Sharing Data.

Use the Site Administration user interface to assign profile realms to your sites. View or update the profile realm in the Sites Realm control. See Editing a Site.