What is a VPN
A VPN creates an encrypted tunnel between your device and a server. Whatever sits in between — the café network, your internet provider — sees encrypted traffic instead of the pages you open.
How it works, in one sentence
Without a VPN, your connection goes straight from your device to each site you visit, and whoever controls the network in between can see where you are going. With a VPN, that connection first travels encrypted to the VPN server, and goes out to the internet from there.
The practical result: the network in between stops seeing the sites you open, and sites see the server's address instead of yours.
What it is actually useful for
Networks you do not control. Airport, hotel or café wifi. You do not know who runs it or what it records.
Remote work. Connecting from outside the office without exposing the connection on someone else's network.
Restrictive networks. When a network blocks services by domain name or by IP address.
Privacy from your provider. Your carrier sees that you connect to a server, not the list of sites you open.
What a VPN does NOT do
It does not make you anonymous. If you sign in to an account, that service knows who you are, VPN or not. No VPN can change that.
It does not protect you from malware. It is not antivirus. If you download something harmful, the VPN will not stop it.
It does not clear cookies or browser tracking. Browser fingerprinting still works.
It cannot guarantee access to any service. Any site can block VPN addresses whenever it wants.
Be wary of any VPN promising otherwise. If someone promises you total anonymity, either they do not understand the product or they are counting on you not understanding it.