The standard way routers usually work is that they have at least 2 distinct network interfaces (network cards). Each interface is connected to either a private or a public network. Geo Router uses Network Address Translation, hence, it can do the job even with a single network interface with a single IP address. There is no configuration is needed, Geo Router configures itself automatically.
Geo Router acts as a server that receives connection requests from all over the world. Internet users that connect to Geo Router are not exposed to the details of routing and IP address translation which happens behind the scenes. To them Geo Router appears as a regular server. When Geo Router forwards network traffic to specified route targets (servers that provide the actual content), it performs IP address translation. This translation makes the traffic processed by Geo Router look like it originated on Geo Router. Geo Router places its own IP address on each packet. This helps to strengthen security on content servers by adding firewall rules that allow only the network traffic from Geo Router.
Multiple Geo Routers can work in a chain. That allows splitting and merging traffic from multiple countries.