Opera VPN works only through the Opera web browser, and it shouldn't be used for sensitive communications. Once very fast, Opera's VPN connections were painfully slow in our most recent tests. The Opera VPN mobile apps, which were full-fledged VPN services that performed decently in our 2017 tests, unfortunately closed up shop at the end of April 2018. There's one good feature, though: Opera VPN streamed Netflix successfully from all of its server locations (there are only three of them), which is more than many paid VPN services can do.
The practical uses for a VPN service are plentiful. Want to access a website that your ISP has blocked? A VPN puts that website just one click away. Want to access the US version of Netflix from the UK? Just set your VPN to a US location and you're there. Want to access porn without your ISP or your business knowing about it? Want to download torrents without being blocked by your ISP? It's easy.