What a VPN does and does not do
A quick guide to virtual private networks
Virtual private networks (VPN) are applications that protect the internet connections made from your device. It does so in the following two ways:
Encrypting your internet connections
Hiding your IP address
To use a VPN, you can install software (i.e., a VPN client) from a VPN service provider. The client connects to the VPN server of the provider, and both the client and server deliver encrypted internet connections that hide your IP address.
The diagram below gives an overview of how this works:
To explain the diagram:
When you connect to the internet from your device, the VPN client encrypts the request and directs it to the VPN server.
The VPN server decrypts the request it receives and then forwards it with its own IP address to the intended recipient (for example the server of the website you are trying to access).
The response from the recipient (the website server) is sent back to the VPN server using the IP address of the VPN server.
The VPN server encrypts the response and forwards it to your device using the IP address of your device.
The VPN client on your device decrypts the response so that your device can display the website you want to access in your browser.
By using a VPN, you can conceal your IP address from internet service providers and website operators. This can help reduce the ability to track your browsing across the web.
However, VPNs do not protect you from everything. For example, VPNs do not prevent browser fingerprinting, which is a form of tracking that uses different pieces of information (such as your browser version, device type and operating system) to build behavioural profiles of you.
Additionally, since the VPN server decrypts the internet communications from your device, that server can see all the websites that you visit using the VPN service. It is therefore important to select VPN service providers that do not access this data or share it with third parties.