For example, when your computer is connected to a VPN, the computer acts as if it's also on the same network as the VPN. All of your online traffic is transferred over a secure connection to the VPN. The computer will then behave as if it's on that network, allowing you to securely gain access to local network resources. Regardless of your location, you'll be given permission to use the internet as if you were present at the VPN's location. This can be extremely beneficial for individuals using a public Wi-Fi.
Some VPNs will also let you define the specific context in which the VPN functions. TunnelBear VPN, in particular, lets you mark a network as trusted and will only activate when you're not connected to one of these trusted networks. This will protect you from bad guys, but it will leave you open to tracking and surveillance by governments and your ISP when you're on trusted networks.
If VPN connections get blocked by your network because of strict network management or government censorship, TorGuard offers a “stealth” connection to avoid deep packet inspection. Specifically, TorGuard uses Stunnel (a clever portmanteau of SSL and tunnel) to add an extra layer of encryption and make your traffic look like normal, secure Web traffic. If you’re having connection issues, you can enable Stunnel with a checkbox on the main application window, but only if you select TCP from the protocol list. (Otherwise, the box is unclickable, with no explanation as to why.)
Trusting a VPN is a hard choice, but IVPN’s transparency goes a long way toward proving that its customers’ privacy is a priority. Founder and CEO Nick Pestell answered all our questions about the company’s internal security, and even described the tools the company used to limit and track access to secure servers. The top VPN services gave us a variety of answers to these questions, some of which were frustratingly vague. ExpressVPN was the only other company to outline these controls and assure us that these policies were well-documented and not half-practiced.
While you're connected to a VPN, all your network traffic passes through this protected tunnel, and no one—not even your ISP—can see your traffic until it exits the tunnel from the VPN server and enters the public internet. If you make sure to only connect to websites secured with HTTPS, your data will continue to be encrypted even after it leaves the VPN.