VPN

VPN (Virtual Private Network) is a way of creating a private, encrypted connection between two points across a public network like the internet. Traffic inside the tunnel is encrypted and only readable by the two ends – so a VPN between your phone and a VPS, for example, makes your traffic unreadable to anyone else on the same WiFi network, and lets that VPS act as a trusted relay back to your home or office network.

VPNs are commonly used for two different things that get conflated: hiding your traffic from your local network or ISP (what most commercial “VPN” apps sell), and securely connecting two private networks together over the internet (the use case most of this site focuses on). Same underlying technology, different goal.