You know that HTTPS (Secure HTTP) and VPN (Virtual Private Network) are a more secure way to browse the web but what exactly happens behind the scenes when you use either of these options? Why do you need to use a VPN when you have already turned on HTTPS? The Privacy Team at Google has recently added a couple of short and useful videos toYouTube that try to explain technical jargon like HTTPS, VPN, WPA (for secure Wi-Fi) in simple English and why these are important. Take a look.
A VPN is a virtual private network. VPNs are commonly used by businesses so that workers can securely access the company computers when they are not at the office. In the typical situation there is a server inside of the company that has VPN server software and the worker’s computer has VPN client software.
When you go to a web site that starts with https it is using SSL to encrypt your data. When you type in your username and password on an https web page it is first encrypted, and then sent and the computer on the other end then can decrypt it. If I am capturing your traffic I will not see what your user name and password are. The trick is that the other web site has to support https. Yahoo mail for example will encrypt my username and password, but then reverts to normal http so that anyone could read my mail if I am using unsecured public WIFI