Debian is a widespread Linux distribution, that is used mainly on PC's, still lots of people have begun using it lately as a web server Operating System as well, due to the stability and protection it offers. The latter is a result of the fact that Debian is developed and supported by a large number of qualified volunteers around the globe, which means that any patch which is necessary to fix a particular issue is released in a matter of days. The very same community can also help with any question or issue which a user may ever experience, due to the fact that they can be contacted via e-mail using mailing lists and a competent response will be sent in no more than 15-20 min. The advantage here is that all of your questions will be replied by the same people who have developed the Operating System itself and they have an in-depth knowledge of how it works. As Debian is provided for free, you won't need to pay any license fees to use it and you'll be able to personalize it as much as you want or need. This is valid for the Operating System as well as the 30.000+ software packages that are readily available for it.