VPN Learning lawful use primer
Educational

General information about lawful VPN use, not legal advice. Follow the law where you are and the rules of any network or device you use. Responsible use

Glossary

VPN terms in plain language

Short definitions of the words used across the guide, each linked to the articles that explain it in context.

Terms

21 of 21 terms

Acceptable use policy
The rules an employer, school or network operator sets for using its networks and devices. They often say whether personal VPNs are allowed.

Explained in: Using a VPN lawfully and responsibly

Captive portal
The sign-in or terms page a hotel, cafe or airport network shows before it lets you online. A VPN usually cannot connect until you have completed it.

Explained in: Troubleshooting common VPN problems

DNS
The Domain Name System, which turns a name such as example.org into the numeric address your device connects to. Whoever answers your DNS lookups can see which sites you look up.

Explained in: What a VPN does, and what it does not, Check that your VPN is working

DNS leak
When your device sends DNS lookups outside the VPN tunnel while the VPN is on, so your network or internet provider can still see which names you look up.

Explained in: Check that your VPN is working

Encryption
Scrambling data so that only someone with the right key can read it. A VPN encrypts traffic between your device and the VPN server.

Explained in: What a VPN does, and what it does not, Protocols and settings in plain language

HTTPS
The encrypted version of the web protocol, shown by a padlock in most browsers. It protects the content of your traffic with a website whether or not you use a VPN.

Explained in: What a VPN does, and what it does not

Independent audit
A review of a provider's systems or policies by an outside firm. Its value depends on what was in scope, when it was done and whether the report is published.

Explained in: How to evaluate a VPN provider without taking claims on trust

Internet provider (ISP)
The company that connects your home or phone to the internet. Without a VPN it can see which servers you connect to; with one, it sees that you are connected to a VPN.

Explained in: What a VPN does, and what it does not

IP address
The numeric address that identifies a connection on the internet. With a VPN on, websites see the VPN server's address instead of yours.

Explained in: What a VPN does, and what it does not, Check that your VPN is working

IPv6
The newer version of internet addressing. If a VPN only handles the older IPv4, some traffic can travel outside the tunnel unless IPv6 is handled or turned off.

Explained in: Check that your VPN is working, Protocols and settings in plain language

Jurisdiction
The country whose laws apply to a provider. It affects what data the provider can be legally required to keep or hand over.

Explained in: How to evaluate a VPN provider without taking claims on trust, Using a VPN lawfully and responsibly

Kill switch
A setting that blocks internet traffic if the VPN connection drops, so nothing is sent outside the tunnel by accident.

Explained in: Protocols and settings in plain language, Check that your VPN is working

Managed device
A laptop or phone administered by an employer or school. Its owner sets the rules, and installing your own VPN on it is usually not allowed.

Explained in: Setting up a VPN on your own devices: the concepts, Using a VPN lawfully and responsibly

No-logs policy
A provider's statement that it does not keep records of your activity. It is a promise, not a technical fact; look for independent evidence and read what exactly is excluded.

Explained in: How to evaluate a VPN provider without taking claims on trust

Public Wi-Fi
A shared network in a cafe, hotel, station or similar place. Its operator, and sometimes other users, may be able to observe unencrypted traffic.

Explained in: What a VPN does, and what it does not, Decide what you need before you choose anything

Split tunnelling
A setting that sends only some apps or destinations through the VPN and the rest directly. Useful, but it means part of your traffic is not covered.

Explained in: Protocols and settings in plain language

Threat model
A plain statement of what you want to protect, from whom, and how much effort is reasonable. It decides whether a VPN helps at all.

Explained in: Decide what you need before you choose anything

Tunnel
The encrypted connection between your device and the VPN server. Traffic inside it cannot be read by the networks it passes through.

Explained in: What a VPN does, and what it does not

VPN (virtual private network)
A service or setup that carries your traffic through an encrypted tunnel to a server, which then connects to the internet on your behalf.

Explained in: What a VPN does, and what it does not

VPN protocol
The set of rules a VPN uses to set up the tunnel and encrypt traffic. Common open protocols include WireGuard, OpenVPN and IKEv2 with IPsec.

Explained in: Protocols and settings in plain language

WebRTC
A browser feature for calls and video. In some configurations it can reveal your real IP address to a website even with a VPN on.

Explained in: Check that your VPN is working