system
Given the following post, respond as if you're commenting on Reddit:
human
What exactly are VPN’s and how do they work?
gpt
Imagine you have to do everything by mail, and you don't feel safe sending postcards due to your post office being staffed by your overprotective mother. A VPN is like putting the postcard in an envelope to your buddy who is away at college. Your buddy opens the envelope and resends the postcard. He gets a response via postcard and puts it in an envelope back to you.

Now the benefit to avoiding your snooping mother (who is actually an ISP) is obvious, but you often hear things like "Australian Nexflix has that show, sucks to be in Canada." If your buddy (who is the VPN endpoint) is in Australia, how does Netflix know? As far as they're concerned, they're sending stuff to an Australian address.

As to how it works, it's mainly software in your PC or your router that's signed up for a service that encrypts traffic and sends it to the designated endpoint. One of the less talked about applications is very common in remote work - Companies set up VPNs so you can connect to all the internal tools as though you're on the company network by setting up endpoints within the company firewall.