Not all Android devices have a built-in firewall feature.

Without a root user, this functionality can be ensured by downloading the application from the Google Play store. Unfortunately, the operation of such an application is usually based on redirecting the connection to the newly created local VPN profile. As a result, we can not use PureVPN and Firewall at the same time.

In short, it is about the functionality that allows restricting another application access to the Internet (via WiFi, and / or celluar).

It can also be in the form of Split Tunneling, where apart from selecting whether the application is to be connected via VPN, it gives the possibility to choose one of three options: block, connect normally, connect via VPN.