A
AES (Advanced Encryption Standard)
The encryption algorithm used by most VPNs. AES-256 (256-bit key) is the gold standard—used by governments and militaries worldwide. Considered uncrackable with current technology.
Auto-Connect
Feature that automatically connects to VPN when your device starts or when joining untrusted networks. Essential for consistent protection.
B
Bandwidth
The amount of data that can be transmitted over your connection per unit of time. Measured in Mbps (megabits per second). VPN shouldn't significantly reduce your bandwidth.
Browser Fingerprinting
Technique websites use to identify you by your browser's unique characteristics (fonts, screen size, plugins, etc.). VPN doesn't protect against this—need privacy browsers.
C
Connection Logs
Records of when you connected to VPN, which server you used, and your real IP. Privacy-focused VPNs don't keep these.
Client
The VPN application you install on your device. Connects to VPN servers and encrypts your traffic.
D
DDoS (Distributed Denial of Service)
Attack that floods your connection with traffic, knocking you offline. VPN protects by hiding your real IP so attackers can't target you directly.
DNS (Domain Name System)
Translates website names (google.com) into IP addresses. VPNs run their own DNS to prevent your ISP from seeing which websites you visit.
DNS Leak
When DNS requests bypass VPN and go to your ISP's DNS servers, revealing which websites you visit. Good VPNs include DNS leak protection.
Double VPN (Multi-Hop)
Routes traffic through two VPN servers instead of one for extra encryption and anonymity. Slower but more secure.
E
Encryption
Process of scrambling data so only authorized parties can read it. VPNs encrypt all traffic between your device and the VPN server.
End-to-End Encryption
Encryption where only sender and recipient can read the message. VPN provides encryption in transit; apps like Signal provide end-to-end encryption.
F - G
Five Eyes / Nine Eyes / 14 Eyes
Alliances of countries that share intelligence. VPNs based in these countries may be subject to surveillance requests. 5 Eyes: US, UK, Canada, Australia, New Zealand.
Geo-blocking
Restricting content access based on geographic location. Streaming services use it to enforce licensing agreements. VPN bypasses geo-blocking by changing your apparent location.
I - K
IKEv2 (Internet Key Exchange version 2)
VPN protocol known for fast reconnection when switching networks (WiFi to cellular). Popular on mobile devices.
IP Address
Unique numerical address identifying your device on the internet. Reveals your approximate location. VPN masks your real IP with the server's IP.
IP Leak
When your real IP is exposed despite being connected to VPN. Usually caused by WebRTC leaks or IPv6 leaks. Good VPNs include leak protection.
ISP (Internet Service Provider)
Company that provides your internet connection (Comcast, AT&T, etc.). Without VPN, they can see all your internet activity.
Kill Switch
Feature that blocks all internet traffic if VPN connection drops, preventing accidental IP exposure. Essential for torrenting and privacy.
L - N
Latency (Ping)
Time for data to travel from your device to a server and back. Measured in milliseconds. Lower is better. VPN adds some latency due to extra routing.
No-Logs Policy
VPN provider's commitment not to store any records of user activity. Should be verified by independent audits, not just marketing claims.
NordLynx
NordVPN's implementation of WireGuard protocol with added privacy features. Currently the fastest VPN protocol available.
O - P
Obfuscation
Technology that disguises VPN traffic as regular HTTPS traffic. Used to bypass VPN blocks in countries like China.
OpenVPN
Open-source VPN protocol. Very secure and flexible. Slower than WireGuard but more configurable. Available in UDP (faster) and TCP (more reliable) versions.
P2P (Peer-to-Peer)
File sharing directly between users without a central server. Used by torrents. Some VPN servers allow P2P traffic, others don't.
Protocol
The set of rules VPN uses to establish secure connections. Common protocols: WireGuard, OpenVPN, IKEv2. Each has different speed/security tradeoffs.
R - S
RAM-Only Servers
Servers that run entirely in RAM with no hard drives. All data is wiped on reboot, making it impossible to seize user data.
Smart DNS
Technology that only routes DNS requests through VPN servers for geo-unblocking. Faster than full VPN but provides no encryption or privacy.
Split Tunneling
Feature allowing you to choose which apps use VPN and which use your regular connection. Useful for banking apps that block VPNs.
T - Z
Throttling
When your ISP intentionally slows certain types of traffic (streaming, gaming, torrenting). VPN prevents this by hiding what you're doing.
Tunnel
The encrypted connection between your device and the VPN server. All your traffic passes through this "tunnel," protected from outside observation.
VPN (Virtual Private Network)
Technology that creates an encrypted connection over a public network, hiding your IP address and protecting your traffic from surveillance.
WebRTC Leak
Browser feature that can expose your real IP even when connected to VPN. Good VPNs include WebRTC leak protection; you can also disable WebRTC in browser settings.
WireGuard
Newest VPN protocol. Much faster and more efficient than OpenVPN with comparable security. Only ~4,000 lines of code (vs 100,000 for OpenVPN), making it easier to audit.
Ready to Get Started?
Now that you understand the terminology, choose a VPN with confidence. 30-day money-back guarantee.