Which VPN service/app is best for safeguarding my browsing activity.

The thread has not been reviewed by Editors yet. Readers are advised to use their best judgement before accessing this thread.
This thread will be reviewed shortly.
If you think this thread contain inappropriate content, please report to webmaster.
I want to know as to which VPN app is best for securing my browsing activity. Also I want to know whether the service provider or the search engine knows about the browsing history as data is exchanged between sites.

How exactly VPN functions, please explain in layman's language and not in a very technical terms.