A Site-to-Site VPN is for connecting a network to maXwan devices, rather than maXvpn which connects a single computer to maXwan devices; therefore, extending the company's network.
Where would you use Site-to-Site VPN?
An example of an application in which Site-to-Site VPN would be ideal is a company that manages various water treatment plants. They require information collected from data loggers via sensors at various sites in NSW and QLD - to be transmitted and made available to several different servers for reporting and monitoring. Each data logger has a maXwan (Fixed IP address) and is part of a subnet; therefore forming one Site-to-Site VPN. In the image below one server is allocated to NSW, one server is allocated to QLD and the third server is a back up of all data. Information from the data loggers is transmitted via a router to the applicable servers and multiple users can access and monitor the data as required.