A VPN sends everything your device does through an encrypted tunnel to a server somewhere else, and lets that server talk to the internet on your behalf. The websites you visit see the server's location instead of yours, and whoever runs your network sees only that you are connected to the server.
That is genuinely useful, and it is much narrower than the advertising suggests. A VPN does not make you anonymous. It changes who can see what you are doing. It does not remove them.
What the situation looks like without one
When you load a page, your request passes through your router, your internet provider, and a chain of other networks before it arrives. Modern sites are encrypted, so those intermediaries cannot read the contents.
They can still see the destination. Your provider knows you connected to a particular site, when, and roughly how much data moved. On a café or hotel network, the operator of that network can see the same. This is the ordinary state of the internet, and it is what a VPN is aimed at.
What changes when the VPN is on
Your device builds an encrypted tunnel to the VPN's server before anything else happens. Every request goes down that tunnel first.
Two things follow. Your internet provider now sees one long encrypted connection to one address, and cannot tell which sites are inside it. And the sites you visit see a request arriving from the VPN server, so they attribute you to its location rather than yours.
What a VPN genuinely gives you
- Cover from the network you are on. Useful on public Wi-Fi, and useful if you would rather your provider not build a record of every site you open.
- A different apparent location, which is why it works on region-locked streaming catalogues, when the service has not detected the VPN.
- A route around network-level blocking, where a country or an employer blocks sites at the network.
- Separation of your home address from your traffic, so sites cannot infer roughly where you live from your IP.
What it does not give you
This is the part the adverts skip.
| Claim | Reality |
|---|---|
| "You are anonymous" | Log in to anything and you have identified yourself. Your account is you, whatever the IP says. |
| "You cannot be tracked" | Cookies and browser fingerprinting do not care about your IP address. |
| "Your data is secure" | Sites were already encrypted. The tunnel protects the path, not the destination. |
| "You are protected from viruses" | A VPN moves traffic. It does not inspect what you download. |
| "Nobody can see your browsing" | The VPN provider can. You moved the trust, you did not remove it. |
A VPN does not hide you from the internet. It changes which single company is in a position to watch you: no longer your internet provider, now the VPN.
Which is why the provider is the whole question
Every VPN can see the traffic your provider used to see. The entire value of the product rests on that company choosing not to look and not to keep records. Independent audits of that claim exist and are worth checking. Jurisdiction matters, because a company can be compelled by the country it operates in. And the cases where a "no logs" provider turned out to have logs are all findable, which is a useful habit before subscribing.
Free VPNs are a bad trade
Running VPN servers costs real money. A service with no subscription is being paid another way, and the asset it holds is a complete record of its users' browsing.
Some free providers have been caught injecting adverts, selling browsing data, or renting out users' connections to third parties. The economics are the same as in most free apps, with the difference that here the product is specifically the thing you installed it to protect.
Leaving it on all the time
A permanent tunnel means every packet takes a detour, so latency rises and throughput usually falls. On a phone it also keeps a connection alive continuously, which is a steady background draw on a battery that is already ageing.
Most people are better served by switching it on deliberately: on untrusted networks, when travelling, when the location genuinely matters. Leaving it running permanently mostly costs speed for a benefit that is not always there.
The short answer
A VPN is a tool for a specific job: shifting the point at which your traffic becomes visible, and changing the location it appears to come from. Bought from a provider you have reason to trust and used for those two things, it does exactly what it says. Bought as a general shield against being watched online, it is protecting a small part of a much larger surface.