Debian is a widespread Linux distribution, that's used mainly on desktop computers, still lots of people have started using it lately as a web server Operating System too, because of the stability and protection it offers. The latter is a consequence of the fact that Debian is developed and supported by thousands of qualified volunteers around the globe, so any patch that is required to fix some issue is released within a matter of days. The very same community will also help with any question or issue that a user may ever encounter, since they can be contacted through electronic mail using mailing lists and a competent response will be sent in around 15-20 minutes. The advantage here is that all of your queries will be answered by the same people who have designed the Operating System itself and they have a detailed 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 can personalize it as much as you want or need. This is valid for both the Operating System as well as the 30.000+ software packages that are readily available for it.