Prompt Almanac

5 min read2 sourcesUpdated

What Is a VPN and What Does It Actually Do?

What a VPN does, what it hides, what it cannot hide, and when it is worth using.

TL;DR

  • A VPN (virtual private network) sends your internet traffic through an encrypted tunnel to a server run by the VPN company, and the websites you visit see that server's address instead of yours.
  • It hides your browsing from the Wi-Fi network and your internet provider, which is useful on public Wi-Fi.
  • It does not make you anonymous: the VPN company can see your traffic, and sites can still recognise you through logins and cookies.
  • It does not stop malware or phishing.

How a VPN works #

Normally your device talks to a website through your Wi-Fi router and your internet service provider (ISP). Each of them can see where your traffic is going. With a VPN, an app on your device first wraps your traffic in encryption and sends it to the VPN company's server. That server then talks to the website for you [1].

Two rows comparing traffic without a VPN, where the ISP can see the site, and with a VPN, where the ISP sees only encrypted data going to the VPN server
Without a VPN the ISP sees the sites you visit. With a VPN it sees only an encrypted connection to the VPN server. (tap or click the image to open it full size)

The encrypted link between your device and the VPN server is called the tunnel. Anything that is not the VPN company, including the café Wi-Fi, can see that you are connected to a VPN server, but not what you are doing inside the tunnel.

What a VPN hides, and what it does not #

Hidden by a VPN?
Which sites you visit, from your Wi-Fi and ISPYes
Your home IP address, from the sites you visitYes, the site sees the VPN server's address
Your activity, from the VPN companyNo. It carries your traffic, so you are trusting it instead of your ISP
Who you are, when you log in to an accountNo
Tracking cookies and browser fingerprintsNo
Viruses, scams and phishingNo [2]

Some countries and services block or restrict VPN use, so check local rules before relying on one.

When a VPN helps #

  • Public Wi-Fi. In cafés, airports and hotels, a VPN keeps other people on the network from watching your traffic. Most sites already use HTTPS, which encrypts the page content, so the gain is mainly hiding which sites you visit [2].
  • Hiding your browsing from your ISP. You swap trust in your ISP for trust in the VPN company, so choose carefully.
  • Working remotely. Companies use VPNs to give staff secure access to internal systems.

How to choose a VPN #

  • Prefer a provider that has had its no-logging claims checked by an independent audit.
  • Be wary of free VPNs. Running servers costs money, so the business model may be your data.
  • Check where the company is based and what it says about logs in plain language.

FAQ #

In most countries yes, but some restrict or ban them, and using one does not make an illegal act legal.

Does a VPN make me anonymous? #

No. It hides your address from sites and your activity from your ISP, but the VPN company and the accounts you log in to can still identify you.

Does a VPN slow my internet down? #

Usually a little, because traffic takes a longer route and is encrypted.

Sources #

All sources accessed 2026-10-27.

  1. What is a VPN? Cloudflare Learning Center. https://www.cloudflare.com/learning/access-management/what-is-a-vpn/
  2. Are Public Wi-Fi Networks Safe? What You Need To Know. Federal Trade Commission consumer advice. https://consumer.ftc.gov/articles/are-public-wi-fi-networks-safe-what-you-need-know