Universal Containers (UC) maintains multiple customer-facing sites, but only one profile for all customer users.

This option allows UC to grant customers access to the appropriate site. Site membership is a feature that defines which users can access a site and what permissions they have. UC can assign the profile for all customer users to the site membership of each site and specify the default page access and object permissions for that profile. UC can also assign permission sets to the site membership togrant additional permissions to specific users4