A VPN (virtual private network) creates an encrypted tunnel from your device to a VPN server and sends your internet traffic through it. Your local network and ISP see only encrypted traffic to the VPN server, and websites see the VPN server's IP address instead of yours.
How it works
Two kinds of VPN
- Consumer VPNs (NordVPN, Mullvad, Proton VPN…) route your internet traffic through their servers for privacy or to appear in another country.
- Business VPNs connect you to a private company network so you can reach internal systems from home.
What a VPN protects
- Your traffic on untrusted Wi-Fi from snooping and tampering.
- Which sites you visit, from your ISP and local network.
- Your IP address from the sites you visit.
What it doesn't
- It moves trust to the VPN provider, which can see what your ISP used to.
- It doesn't stop tracking by cookies, logins and browser fingerprints.
- It doesn't protect against malware or phishing.
- It can leak: DNS lookups, IPv6 or WebRTC may bypass the tunnel if it's misconfigured.
Protocols
WireGuard (fast, modern), OpenVPN (flexible), IKEv2/IPsec (built into macOS and iOS).
Examples
- Before connecting:
curl -s https://api.ipify.orgshows your ISP's address. After: it shows the VPN provider in the country you chose. - On café Wi-Fi, the network sees only an encrypted stream to one IP: the VPN server.
On a Mac
macOS has built-in IKEv2, IPsec and L2TP clients in System Settings › VPN; most providers ship apps that add their own. While connected, ifconfig shows a utun interface and netstat -rn shows the default route pointing into it.
See it in the app
LightAtom's connections view shows your VPN app's connection to its server alongside every other app's connections.
Frequently asked questions
What does a VPN do?
It encrypts your internet traffic and routes it through a server elsewhere, hiding it from your local network and giving you that server's IP address.
Does a VPN make me anonymous?
No. It hides your IP and traffic from your ISP, but the VPN provider sees it, and websites can still identify you by logins, cookies and fingerprints.
Do I need a VPN at home?
For security, usually not: HTTPS already encrypts most traffic. It's useful for hiding activity from your ISP or changing your apparent location.
How do I know my VPN is working?
Check that curl -s https://api.ipify.org shows the VPN's address, and run a leak test to make sure DNS and IPv6 also go through the tunnel.