While browsing on VPN does my ISP know which sites I'm visiting?

VPN
1

I know the opera vpn works differently, so had to ask.

2

Opera’s VPN is not a true VPN. It’s merely a HTTPS proxy. It’s same as when using SurfEasy browser extension with a browser other than Opera.

Your ISP can’t see which site you’re connecting to. They can only see that you’re connecting to the “VPN” server, which is SurfEasy’s HTTPS proxy server. All data are encrypted using HTTPS, so your ISP only sees encryped data.

The only possible leak is when using the WebRTC functionality, as described below.

https://www.quora.com/Is-Opera-browser-with-in-built-VPN-a-genuine-VPN