VPN
A VPN routes a device's internet traffic in encrypted form through an intermediary server, so that no one along the way can read it. Companies use it for secure access to internal systems, while private users rely on it mainly for privacy and for content that is blocked in their own country.
When you access something on the internet, your data travels through many intermediate stations: your router, the provider that connects you to the internet, and further computers along the way. Each of these stations can, in principle, see which sites you’re communicating with. A VPN inserts an additional layer of protection in between. Your device packages all data so that only one specific external computer can unpack it again. This computer usually sits in a data center and then forwards your requests on your behalf. From the outside, it looks as if the traffic is coming from this computer rather than from you.
What companies and private individuals need tunnels for
The original purpose is business-related. Large companies have internal servers that shouldn’t be reachable from the open internet. Someone working from home can still get in via a VPN, as if they were sitting in the office on the company network. Without this technology, you’d have to expose internal systems openly to the internet for everyone, which would be an enormous security risk.
For private users, it’s usually about two other things. First, confidentiality on unfamiliar networks. On an open Wi-Fi network at a café or train station, the network’s operator can observe the traffic. Second, apparent location: because the intermediary server can be located in another country, websites take you for a user from that country. That’s why VPNs are often used to get around streaming restrictions or blocks.
However, there’s an important limitation that advertising likes to gloss over. A VPN does not make you anonymous. The VPN provider now sees exactly what your internet provider saw before. So you’re only shifting the trust, not eliminating it. And anyone logged into Google will still be recognized by their account, regardless of which country the traffic passes through.
Encryption and the route via the intermediary server
Technically, a VPN consists of two parts: a program on your device and a server at the provider. When the connection is established, both negotiate a secret key that only they know. After that, every data packet is rendered unreadable with this key before being sent. This is called a tunnel, because the data travels through the open internet as if inside a sealed pipe.
A comparison helps: instead of sending a postcard that any mail carrier can read, you put your letter inside a second, sealed envelope. On this outer envelope, only the address of the intermediary server is written. That server opens it, reads the actual destination address, and forwards the contents. The reply takes the same path back.
Which rules govern this packaging is defined by what’s called a protocol, i.e. a technical agreement. Widely used today are WireGuard and OpenVPN, with WireGuard considered faster and leaner. Still, this comes at a cost: the detour via the intermediary server increases response time, and the encryption requires computing power. With games or video calls, this is sometimes noticeably apparent.
VPNs in school Wi-Fi, sponsor advertising, and politics
You’ll most often encounter the term in advertising. VPN services are a billion-dollar market and conspicuously sponsor many YouTube videos and podcasts. The promises made there are usually exaggerated: a VPN does not protect against viruses, does not protect against phishing emails, and does not stop you from entering your own password on a fake website.
In everyday life, you also come across it in schools and companies, where networks are filtered and VPNs are often explicitly banned. In the news, on the other hand, the term usually appears in a political context. In countries with heavily censored internet, download numbers for VPN apps regularly spike sharply whenever governments block social networks. Some states have therefore started restricting or penalizing VPN use itself.
This should be distinguished from the Tor network. Tor sends data through several independent stations and is designed for anonymity, but is slow as a result. A VPN has only one intermediary station and one operator, making it fast and practical for everyday use. Both are tools for different purposes, not substitutes for one another.