Linux is an Operating System, which isn't that popular for desktop machines, but is one of the most popular OSs for servers. It's totally free, so you shall not have to pay any license charges as part of your hosting payments. Linux is furthermore thought to be the most secure Operating System out there and due to the permissions which files have along with the file types that can be run, virus files which could infect a regular personal computer will simply not be executed on a Linux-based web server. Also, the OS is free, so it can easily be changed without any limits, so as to satisfy the needs of the hosting company and their clients. This also means that unwanted software packages could be removed to make the Operating system lighter and swifter, which could directly result in a lot better hosting server performance. A lot of Linux machines have the Apache web server installed on them, as this software is also totally free, quick and reliable. It's the most commonly used web server around and is a part of the LAMP bundle that a lot of script applications, including WordPress and Joomla™, require. LAMP is an abbreviation for Linux, Apache, MySQL and PHP.