VPNs were originally used to allow remote workers to log in to corporate networks remotely over a secure connection.
In essence, a VPN works by routing all your Internet traffic through another computer, which could be on the other side of the planet. For all intents and purposes, it’ll appear you are browsing the Internet through that remote computer.
I spoke to Linux User & Developer back in 2018 who helped me dig into all the pros and cons of VPNs on Linux.