system
Given the following post, respond as if you're commenting on Reddit:
human
What is a VPN? Should I use one? Which one?
gpt
Think of data traffic like road traffic, with your data being freight on the back of pickup trucks. Think of your home network as an island, with a bridge connecting it to the mainland (built and maintained by your Internet provider). If you want to send stuff to someone, or get stuff sent to you, the stuff gets loaded onto the back of a pickup truck and driven from and to your island.

Now let's say your Internet provider is a bit nosy and installs cameras on the bridge, recording everything that's on your pickup trucks. Of course you don't really transport anything embarrassing or illegal, but you still don't really like the general feeling.

So, what do you do? The solution for most types of VPN is as easy as it is straightforward. On the way out, before your pickup trucks go over the bridge, they stop at a loading yard, where they are driven into large 18 wheelers (just like in "Knight Rider"). These drive over the bridge, to some other loading yard. This can be anywhere, from somewhere close by to being on the other side of the world. Here, the pickup trucks drive out of the 18 wheelers and get sent on their way.

Now all your Internet provider sees are 18 wheelers going between your loading yard and some loading yard somewhere in the world, with no idea what's loaded onto the pickup trucks inside. They also don't know where the pickup trucks are coming from and where they are driving. Also, neither does the final destination of the pickup trucks, they only see them driving from and to your second loading yard outside your island.

All you need to set this up is rent or buy a loading yard (a VPN tunnel endpoint) somewhere in the world -- and (if you only rent one) trust that the guy operating it is not stealing, recording, or tampering with what's on your pickup trucks.