A virtual private network allows you to browse the internet without exposing your personal internet connection.
It's kind of like having a friend go to the grocery store for you. You'll still make the requests, and get the items you want but you won't be the one everyone sees shopping.
There are literally hundreds of reasons why you might want to protect your personal internet connection. Some people prefer additional anonymity when browsing online; others want to keep advertisers from tracking their behaviors. It may also be that you're simply trying to access Netflix while studying or traveling abroad and missing shows due to region locking.
To understand how VPNs work, let's learn a little about how the internet works. We'll start with the example of an ISP, but the same concept holds true for public wifi networks, employers, cell phone plan providers, etc.
When you access the internet from any of your devices, your request must first go through your internet service provider (also called an ISP). Your ISP is responsible for being the middleman between you and the internet. You request Facebook.com, and your ISP connects to Facebook and sends the data back to your device.
Your connection looks like this:
During this intermediary exchange, your ISP is able to see all of your network traffic. They know that it's you requesting Facebook.com, and exactly what you're looking at or doing there. Everything you do passes through their pipes, clear as day for them to look at and log for future use.
Using a VPN hides your IP address and encrypts your network traffic, effectively stopping this from happening.
Encryption is the process of protecting data in such a way that only authorized parties can read it. Anyone who isn't authorized (hackers, spies, snoopers) just see unintelligible bits and bytes.
If you were to first connect to a VPN and then request Facebook.com though, your connection would look like this:
Your ISP connects you to the VPN, which creates a tunnel between you and the VPN server, which acts as your gateway to the internet. To your ISP, it just looks like you're accessing the VPN server. They're unable to see what your VPN server is requesting for you.
Now, I know what you're thinking:
"I don't do anything wrong, so I probably don't need a VPN."
This argument couldn't be more wrong.
The truth is that VPNs are sometimes used for nefarious purposes, but that's not the norm. In fact, the vast majority of VPN usage is routine and commonplace -- and has been so for years.
Many people may already have experience using a VPN through their workplace. Chances are, if you're a remote employee, or work from the field so to speak, your company asks you to log into their internal network through a VPN. It's an easy way to securely and privately access company resources while not on premises.
One of the neatest things about using a VPN is that you can change your location. Most VPN service providers have multiple locations that you can connect to at your leisure. So you can appear to be coming from another city, another state, or halfway around the world!