Glossary
VPN terms, defined properly
The answer first, then why it matters, then a tool that lets you see it rather than take our word for it. Several of these terms are widely explained wrongly, and where that is true the page says so.
What is a VPN protocol?
A VPN protocol is the set of rules deciding how the tunnel is built and secured — how your device and the server authenticate each other, agree on keys, and package traffic. WireGuard, OpenVPN and IKEv2 are the ones in use, and they differ far more in speed and in what networks allow than in encryption strength.
What is a VPN router?
A VPN router runs the VPN itself, so every device on the network is covered without installing anything on them. It is the only practical way to protect a smart TV, a games console or anything else that will not run a VPN app — and the trade is that it covers everything, whether you wanted it to or not.
What is VPN passthrough?
VPN passthrough is an old router setting that let PPTP and L2TP/IPsec connections work through NAT. It exists because those protocols predate NAT and break without help. If you are looking at it on a current router, the short answer is that you almost certainly do not need it.
What is a VPN concentrator?
A VPN concentrator is enterprise hardware that terminates a large number of VPN connections at once — typically staff connecting into a corporate network. It is a business networking device, not a consumer product, and if you arrived here from a consumer VPN question it is almost certainly not what you are looking for.
What is a VPN provider?
A VPN provider is the company operating the servers your traffic goes through — which makes choosing one a question about the company, not the technology. Whichever provider you use can see the traffic leaving their end, so what matters is their logging policy, their jurisdiction, and whether anyone has audited it.
What is a VPN?
A VPN — virtual private network — is an encrypted connection between your device and a server somewhere else. Everything you send travels inside it, so the networks in between can see that you are connected but not what you are doing, and the sites you visit see the server’s address instead of yours.
What is a VPN tunnel?
A VPN tunnel is the encrypted path your traffic takes between your device and the VPN server. Your ordinary packets are wrapped inside new ones addressed to the server, so anything carrying them sees only the outer wrapper — the real destination is inside, and encrypted.
Covered elsewhere on the site
These already have a full article, so there is no second page here competing with it.
- Kill switchWhat happens to your traffic when the tunnel drops.
- DNS leakQueries escaping the tunnel while it still says connected.
- WebRTC leakA browser API that reveals your address regardless of proxy settings.
- Split tunnellingSending only some traffic through the tunnel.
- No-logs VPNWhat the claim means and what backs it up.
- Dedicated IPAn address that is yours rather than shared.
Definitions are cheap. Measurements are not.
Every term here has a free tool behind it that shows you the real thing on your own connection — what your address gives away, which resolver is answering for you, whether your browser is leaking around the tunnel.