VPN
Also known as: virtual private network
A service that encrypts your internet traffic and routes it through a server in another location.
A VPN creates an encrypted tunnel between your device and a VPN provider's server. Your ISP and local network only see traffic to the VPN; the destination sites only see the VPN's IP, not yours.
VPNs are useful against local-network surveillance, geoblocking and IP-based fingerprinting. They are not a complete privacy tool: the VPN provider can see what the ISP used to see, and they don't stop in-browser tracking. Pair a VPN with an ad and tracker blocker for layered defence.