Portal users enable you to authenticate the people who access your portal and assign appropriate security for the documents and objects in your portal. Users can be imported from external user repositories, created through the portal, created through invitations, self-registered, or just guests (unauthenticated users).
Default profiles are defined through special users, created in the Default Profiles folder (accessed through the Default Profiles Utility). These special users cannot log in to the portal. They are solely used to assign settings to new users.
You can use authentication sources to import users that are already defined in your enterprise in existing user repositories, such as Active Directory or LDAP servers. After users are imported, you can authenticate them with the credentials from those user repositories. You can also import user information (such as name, address, or phone number), which can then be used to populate user profiles or can be passed to content crawlers, remote portlets, or federated searches as user information.
You can invite users to your portal through invitations, making it easy for them to create their own accounts and letting you customize their initial portal experiences with content that is of particular interest to them.
The portal lets you create multiple guest users. This is useful when you want to have different user experiences for different sets of unauthenticated users. You can accomplish this by creating a guest user for each group of unauthenticated users that you want to see a different user experience. You then associate each guest user with a different experience definition, customize the My Page for each guest user, and use experience rules to direct the guest users to the appropriate experience definition.
For example, you could create one guest user for employees that have not yet logged in to the portal and one for customers visiting your portal. The My Page for the employee guest user would include the login portlet so employees can log in. The My Page for customers might include information about your company, such as contact numbers and descriptions of your products or services. You would create two experience definitions, associating one guest user with each. Then you would create two experience rules that would direct users to the appropriate experience definition based on the URL they use to access your portal.