Let's talk about what happens when you use a VPN app on your computer or mobile device. Any VPN app will require an existing network connection to be able to connect to the VPN service provider. This means that even if you set your VPN app to automatically launch when your device boots, there will be a period of time when your computer is connected to the internet directly, not through your VPN.
If HTTP browsing is a postcard that anyone can read as it travels along, HTTPS (HTTP Secure) is a sealed letter that gives up only where it’s going. For example, before Wirecutter implemented HTTPS, your traffic could reveal the exact page you visited (such as https://thewirecutter.com/reviews/best-portable-vaporizer/) and its content to the owner of the Wi-Fi network, your network administrator, or your ISP. But if you visit that same page today—our website now uses HTTPS—those parties would see only the domain (https://thewirecutter.com). The downside is that HTTPS has to be implemented by the website operator. Sites that deal with banking or shopping have been using these types of secure connections for a long time to protect financial data, and in the past few years, many major news and information sites, including Wirecutter and the site of our parent company, The New York Times, have implemented it as well.