All You Need To Know About VPN

You're watching a movie. A criminal is trying to evade a crime scene in a sports car on the highway. A helicopter is following the car from above. The car enters a tunnel with multiple exits and the helicopter loses track of the car.

A VPN works just like the tunnel in this movie scene — it connects different roads and turns them into one, and a helicopter can't see what's happening inside the tunnel.

I'm sure many people around you have recommended you a VPN service. They usually tell you that a VPN is great, it lets you watch geo-blocked content, avoid the Great Firewall of China or browse the internet securely. VPNs are great, sometimes. But using a VPN can be as dangerous as not using one if you don't know what you're doing.

What the hell is a VPN?

If you have multiple computers, phones and tablets at home, you are using a local area network. These devices are all connected to the same Wi-Fi network and you can even transfer photos or movies from one computer to another without using the internet. Local area networks are private networks by design.

A VPN is a virtual private network. It lets you remotely connect to a private network. For instance, your office might be using a VPN for remote employees. This way, you can establish a connection with your company's intranet and use your computer as if it were in the office. You're virtually in the office, using your company's Wi-Fi network.

Using a VPN is quite simple. Usually, a company or a developer installs a VPN server on a computer at home, in your office or in a data center. Then, users with the right credentials can connect to this server using a VPN client. There are many VPN clients out there on computers, mobile devices and even routers. Windows, Android, iOS and macOS even come with a basic VPN client in your device's settings.

Let's say you're establishing a VPN connection on your computer. Your computer and the VPN server will start a point-to-point connection and all your network traffic will go through this connection. Think about this connection as a tunnel between your computer and a server. This tunnel is usually encrypted, and everything goes through the tunnel, from one end to another.

Why should I use a VPN?

Many of you probably first started using a VPN for work, especially when you're working from home. There are a few advantages in using a VPN for a company. For example, it lets employees access office servers that aren't connected to the internet, as you're all connected to the same private network. Back in the days before cloud-hosted Office 365 servers or the G Suite, many companies were managing their own email and calendar servers. IT services could force you to connect to the company's VPN first to access your emails and calendar events. It's a good way to protect sensitive information.

But there are a few drawbacks as well. When you use a VPN connection, all network traffic goes through the VPN, including your internet traffic. Your company's IT service could enforce strict browsing rules and prevent you from using Twitter. Or they could even watch and record your internet browsing habits to find a good excuse to fire you later down the road (too much Reddit, kthxbye).

But office environments aren't the only use case for a VPN. If you live outside of the U.S., you know that a VPN can save the day when you're trying to stream something from HBO Now, Netflix's U.S. movie library, Hulu or one of the many streaming services that restrict you from using them abroad.

Many companies provide access to a bunch of servers around the world so that you can pretend you're in another country. As I told you, once you set up a VPN connection, all network traffic goes through a tunnel and HBO's servers will think that they're sending data to a customer in the U.S. They're sending data to an American IP address indeed (the address of the server), but everything is then sent through the VPN tunnel to your device on the other side of the world.

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