Debian is a widespread Linux release, that's used mainly on personal computers, still lots of people have begun using it lately as a web server OS too, due to the stability and protection it provides. The latter is a result of the fact that Debian is developed and supported by numerous qualified volunteers all around the world, therefore any patch that is required to fix some issue is released in a couple of days. The same community will also help with any question or trouble which a user may ever encounter, due to the fact that they can be contacted through email using mailing lists and a qualified response will be sent in no more than 15-20 minutes. The advantage here is that all your questions will be addressed by the same people who have developed the Operating System itself and they have a detailed knowledge of how it works. As Debian is provided for free, you will not 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 the Operating System and the 30.000+ software packages which are available for it.