Linux is the most popular operating system (OS) used by Web hosting providers. This versatile and powerful alternative to Microsoft Windows is available in a variety of free, “freemium” and commercial iterations.
Many hosts - particularly shared hosting providers - default to Linux for hosting packages, so it's by far the market leader. It's also the operating system used by Google to run its vast banks of servers: more than 15,000 and counting.
Many people buy web hosting without giving much thought to the technical details. If you have a low cost shared hosting plan, chances are it's provisioned on servers running Linux. You benefit because: