If you're using the internet, a Virtual Private Network (VPN) is a great tool to have.
What is a VPN and how does it work?
When you are looking at funny cat videos, your device connects to your Internet Service Provider (ISP), such as AT&T, Verizon, Cox, etc. Then your ISP will point you to the cat video you requested.
A malicious entity (hacker, corporations, government) could intercept your data being transferred and find out what you are doing on the internet.
Just like "the cloud is just someone else's computer", a similar thing could be said for a VPN. You are just using someone else's internet to browse the internet. When you connect to a VPN service, it creates a secure connection to this other computer. All the traffic requests, and cat videos, are sent through this tunnel, protecting you from the prying eyes of the nosy entities.
If the nosy entities manage to intercept your data, they would only get a scrambled signal. That's becase the VPN encrypts the communication that is being sent between your device and the device at the end of the tunnel.
Once you pop out at the end of the tunnel, your computer is now considered (virtutally) a part of that network. That means your computer is acting as if it was physically teleported to that part of the world, and connected to that particular network. You even get a different IP address than the one you had before you connected.
So what does that mean for us regular folk, and why should I use a VPN?
My main recommendation for a VPN is when you are on a public wifi, such as a library, hotel, or coffee shop. Even though a wifi has a password, anybody who is on the same network, like the stranger three tables away from you, could look at the wifi traffic and gather some info from the internet traffic you generate.
When you are connected via a VPN, all the things you do are funneled through the tunnel, protecting you from anybody else on the same hot spot.
Location Based Browsing
Another feature of a VPN is being able to go connect through the tunnel, and depending where the VPN is located, your computer would look like it's now located in that same location. If you're traveling outside the country, you would be redirected to that country's version of your favorite search engine or shopping page. Maybe it would be in a language you have a difficult time reading, or some features are not allowed in that county. If you connect to a VPN connected in your home country, then you would be getting the internet you're more familiar with.
This also works for those of you who run services at home. Let's say you are out, and you need access to a device or service that is only accessible while you're inside your home network. You could setup a VPN to connect you to your home network. Then, no matter where you are, you would be able to access those devices or services as if you were at home. Since it's using a secure VPN connection, it's safe.
There are a few down sides to using a VPN. If you use a popular VPN service, that means more people are using the same endpoint. Those other people are also protected from their end of the tunnel to the endpoint. They are also most likely given the same IP address as you. This is problematic, cause many captchas would automatically flag you as a bot, meaing you'd have to fill out many more captchas proving that you're not a bot than you're used to.
Some services recognize you're using a VPN and will prevent you from accessing their services. For example, Netflix has different content being displayed based on your country. If you use a VPN to pop out of another country, like Japan, Netflix would recognize that you're using a VPN and tell you you cannot stream unless you turn it off. They would also display that if you were using a VPN is the same country, say you are using a VPN to connect to your home while you're out shopping.
A lot of VPNs say they're secure, and that they will protect you. Do not fall for their tricks. They are technically correct. They are using secure methods, their tunnels are secure, and they are protecting you from hackers at your local coffee shop.
If they're doing all those things, how is it not secure? It all comes down to what they do with your traffic at the end. If you remember, a VPN just connects you to another computer to basically use their internet. What they can do is log the pages you go to, including metadata such as the time you visited, and how frequently you went there. These logs can then be purchased, breached, commandeered.
If your threat model requires that your internet activity not be logged by your VPN, make sure you check if that particular service keeps logs of some sort.
At the end of the day, it comes back to do you trust the company/people/entity at the end of the VPN tunnel.
If you use a VPN, and it gives you a new IP address, isn't that a form of privacy? Unfortunately, not really. If you're trying to hide from google, meta/facebook, twitter, etc, changing your IP address would not be much of a hindrance for them tracking you on the internet. They can track you by something called fingerprinting. Each company uses different methods to identify you as you travel along the internet.
This isn't in the scope of this post, but companies use things such as the browser you have, the extensions you installed, the computer you use, the fonts that are installed, and that's just the low hanging fruit. I am not well versed in that, but feel free to search for the different techniques companies use to fingerprint you.
So, do you need a VPN?
Possibly. Please check out https://www.doineedavpn.com/ they are more knowledgable, and have the bandwidth to keep up to date, and can help you to pick out the right VPN for you. There are no affiliate links on there, so be assured they aren't trying to sell you anything.