Debian is a preferred Linux distribution, which is used mainly on desktop machines, but a lot 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 direct result the fact that Debian is developed and supported by a large number of qualified volunteers internationally, which means that any patch that's necessary to fix a certain issue is released within a couple of days. The very same community can also help you with any question or problem that a user may ever have, since they can be contacted via e-mail using mailing lists and a qualified response will be sent in around 15-20 min. The advantage here is that all of your questions will be replied by the same people who have created the Operating System itself and they have an in-depth knowledge of how it functions. As Debian is provided for free, you will not have to pay any license fees to use it and you will be able to customize 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.