Debian is a widespread Linux release, that's used primarily on desktop computers, however numerous people have begun using it lately as a web server Operating System too, due to the stability and security it supplies. The latter is a result of the fact that Debian is developed and supported by thousands of qualified volunteers all around the world, therefore any patch that is necessary to fix a particular issue is released within a couple of days. The same community can also help with any question or problem that a user may ever have, because they can be contacted via email using e-mail lists and a qualified 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 created the Operating System itself and they have a detailed knowledge of how it works. As Debian is free, you won't have to pay any kind of license fees to use it and you will be able to customize it as much as you want or need. This is valid for the Operating System and the 30.000+ software packages which are readily available for it.