Because the VPN server you're connected to presents its IP address to whatever web application you're using, by choosing a server located in a different country, you can represent your connection as if you're in a different country. This may be illegal in certain regions, so use caution when doing this. In my testing, some VPN providers could successfully hide their originating country or the fact that they were VPNs, but others were not. You'll probably want to do some testing. Of the services where I did in-depth testing, NordVPN and Hotspot Shield could successfully hide their VPN origins, while StrongVPN and CyberGhost were not.