So, there are a few different types of VPN. The one that I think you are concerned about is one to help obfuscate your traffic/Browsing history on the ISP your using. This is usually a subscription based service provided by a VPN provider, they provide an application you install and run on your computer (some vendors can provide more advanced options depending on your tech level) and pay a charge for the service (there are browser based VPNs but wouldnt put too much faith in them, I occasionally use the Dissenter/Brave browser and that has a "Private window with TOR" option which can be handy). The application then adds in a network adaptor that redirects your traffic through their servers which shows as your IP address. I wouldn't take this as a free ticket to start spamming Boris Johnston into oblivion with rare pepes or ordering hits on the dark web as VPN companies *say* they don't log things, but who can be sure? Setting up a VPN to your home address does exactly that, Creating an encrypted tunnel back to your home network. This allows secure transfer of files from anywhere in the world but that traffic is still logged at an ISP level. More helpful?