Secure Browser VPN, available in Secure Browser PRO, is an advanced security feature that fully encrypts your online activity, loads web pages faster, and gives you access to over 30 locations worldwide. Avast Secure Browser automatically connects to the optimal location to disguise your location.
This extract from the FAQ mentions ‘Secure Browser PRO’ which I would have to believe is different to Avast Secure Browser.
As I understand, if well I also no use those products, Avast browser is a browser with a vpn extension, so you can activate it but only work for the Avasr browser
VPN as standalone product, is for all your pc, mean all other programs not only the browser. Per example to watch netflix content blocked at your country (using Netflix app)