What Is a VPN

A VPN (Virtual Private Network) is a technology that encrypts your internet traffic and routes it through a server in another location, protecting both the content of your communications and your real IP address.

When you use a VPN, an encrypted "tunnel" is created between your device and the VPN server. Your ISP and network administrators cannot see inside the tunnel, and the websites you visit see the VPN server's IP address instead of your actual IP address.

Technically, the VPN client encrypts packets and sends them to the VPN server, which decrypts them and forwards them to the destination site. Return traffic is similarly encrypted, so even if a third party intercepts the communication along the route, they cannot decipher it. This encrypted tunnel operates independently of TLS/SSL, so even HTTP traffic is protected from eavesdropping when routed through a VPN.

Enterprise VPNs and consumer VPNs serve very different purposes. Enterprise VPNs primarily provide remote access to corporate networks, using products like Cisco AnyConnect or GlobalProtect. Consumer VPNs focus on privacy protection, with commercial services like NordVPN, ExpressVPN, and Mullvad being the most well-known.

When You Need a VPN

Using public Wi-Fi: Wi-Fi at cafes and airports is often unencrypted, creating a risk of eavesdropping. Encrypting your traffic with a VPN protects your data from attackers on the same network.
Privacy protection: Useful when you want to prevent your ISP from logging your browsing history or avoid IP-based tracking by advertising networks.
Remote work: Many companies deploy VPNs as a means of securely accessing their internal networks.

However, it is important to understand the limitations of VPN protection. A VPN encrypts the communication path but cannot prevent you from visiting phishing sites or downloading malware. Tracking via browser fingerprinting and cookies is also not blocked by a VPN, so combining multiple countermeasures is essential for privacy protection.

DNS leaks also require attention. If DNS queries travel outside the VPN tunnel even while connected, your browsing destinations are exposed to your ISP. Reputable VPN services operate their own DNS servers and include DNS leak protection. Make it a habit to verify with dnsleaktest.com after connecting.

VPN Protocol Comparison

The latest generation. Fast and lightweight, with only about 4,000 lines of code, making it easy to audit. Currently the most recommended protocol.

Over 20 years of proven track record. Highly compatible and runs on virtually every platform. Slower than WireGuard.

Strong in mobile environments. Maintains the connection even when switching between Wi-Fi and mobile data.

As a practical guideline for protocol selection, WireGuard should be the first choice for desktop environments. WireGuard offers 3-4x higher throughput compared to OpenVPN, and connection establishment completes in under 1 second. However, WireGuard's default design retains the connecting IP on the server side, so privacy-focused VPN services add NAT translation to address this (e.g., NordVPN's NordLynx).

OpenVPN offers both TCP and UDP modes; TCP mode can disguise traffic as HTTPS to pass through strict firewalls. It remains a strong option for connections from corporate networks or heavily regulated regions.

Risks of Free VPNs and How to Choose

Free VPN services may seem attractive but carry significant risks. Cases have been reported where user browsing data is collected and sold to cover operating costs. Bandwidth limits, speed throttling, ad injection, and inadequate encryption are also common issues.

We recommend paid services with independently audited no-log policies. Considering that a few dollars per month can secure your privacy, the cost-performance ratio is favorable.

Here are specific points to check when selecting a VPN provider.

Third-party audit of no-log policy: Verify that the claim of "no logs" has been validated by an independent auditor such as Deloitte or PwC. Mullvad uses RAM-only servers that are physically incapable of storing logs
Legal jurisdiction: Check whether the VPN provider's home country mandates data retention. Five Eyes member countries (US, UK, Canada, Australia, NZ) have intelligence-sharing agreements, so privacy-conscious users prefer providers in non-member countries (Switzerland, Panama, Sweden, etc.)
Kill switch: A feature that blocks all internet traffic the moment the VPN connection drops. Without it, your real IP address is temporarily exposed during disconnections
Speed: VPN traffic is slowed by encryption overhead. With a WireGuard-compatible service, maintaining about 80-90% of your original connection speed is a reasonable benchmark

To learn more about this topic, see What Is a VPN? How It Works, Benefits, and How to Choose One.

Common Misconceptions

Using a VPN makes you completely anonymous: A VPN hides your IP address but cannot prevent tracking via cookies or browser fingerprinting. The VPN provider itself may also retain logs.
Using a VPN makes everything you do safe: A VPN only encrypts the communication path; it does not protect against phishing sites or malware. It should be considered one component of a broader security strategy.

VPN vs. Proxy

VPN

Encrypts all traffic at the OS level. Hides IP address and protects communication content. Slightly slower but highly secure.

Proxy

Relays traffic for specific applications (e.g., browser) only. Usually does not encrypt traffic. Lightweight and fast but limited security.

VPN (Virtual Private Network)