According to an article by Mohammad Taha Khan And Narseo Vallina-Rodriguez in the phys.org web site:
“About a quarter of internet users use a virtual private network, a software setup that creates a secure, encrypted data connection between their own computer and another one elsewhere on the internet. Many people use them to protect their privacy when using Wi-Fi hotspots, or to connect securely to workplace networks while traveling. Other users are concerned about surveillance from governments and internet providers.
“Many VPN companies promise to use strong encryption to secure data, and say they protect users’ privacy by not storing records of where people access the service or what they do while connected. If everything worked the way it was supposed to, someone snooping on the person’s computer would not see all their internet activity – just an unintelligible connection to that one computer.
“However, most people – including VPN customers – don’t have the skills to double-check that they’re getting what they paid for.”
The article then goes on to describe how you can determine if your VPN is doing the intended job.
This article should be required reading for owners of all computers. You can find Is Your VPN Secure? at: https://phys.org/news/2019-02-vpn.html.