Private sites require logins, and users to register to gain access. Sites for an organization’s staff are usually known as Intranet or company sites. The visitor has to be on the organization’s secured network, or use a secure login to gain access to the private site from outside the network.
Sites that are made available to registered users that are outside an organization are known as Extranets and made available to specific customers, clients, or contractors.
These sites are easy to set up and can help eliminate a lot of duplicate efforts in communicating the same information to the set groups of people.