An operating system or OS is the program that, after being loaded into the computer by a boot program, manages all of the other programs on a computer. Essentially, the operating system is the program that allows you to interact with your computer. There are many different operating systems out there, but one operating system stands above the rest as it is by far the most popular OS on the planet. And that operating system is Linux. Most people will likely be surprised to learn that Linux is the most popular OS because most people don't realize that Linux is there half the time. In fact, most people have never heard of any operating system except for the one that their PC or laptop shipped with, which is usually Microsoft Windows. So, your PC runs Windows, and that's nice. But, that router next to your PC is also a computer, and it runs an operating system. That operating system is Linux. When you're surfing the web, the sites that you are visiting are all hosted on servers, which are computers, which means that they are running an operating system. Those countless millions of servers that make up the worldwide web are almost all running Linux. Have you ever wondered why long website URLs have forward slashes instead of backslashes? It's because the Linux operating system uses forward slashes like any sane and rational being would, instead of the bizarre backslashes that Microsoft Windows uses. Only degenerates use backslashes as separators. What about all of the data centers around the world used to assemble, process, store, and disseminate vast amounts of data? Well, data centers run Linux. Do you have a smart TV if so, guess what? The thing that makes your TV smart? That's Linux. Modern cars all have computers. Your onboard computer in your car runs Linux. There are billions of Android devices in service all around the world. Did you know that your Android phone and tablet runs on Linux? Digital Signs, Kiosk, Point of Cell Systems, basically anything that runs a graphical user interface and isn't a desktop or laptop is pretty much always running Linux. Unless, of course, you're a bank. And people wonder why their bank accounts and debit cards are always being hacked.