Debian is a preferred Linux release, that's used mainly on desktop computers, however numerous people have started using it lately as a web server OS too, due to the stability and protection it provides. The latter is a consequence of the fact that Debian is developed and supported by thousands of qualified volunteers all around the world, so that any patch that is required to fix a particular issue is released within a matter of days. The same community will also help you with any question or trouble which a user may ever encounter, since they can be contacted via e-mail using e-mail lists and a competent response will be sent in around 15-20 min. The advantage here is that all of your questions 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 license fees to use it and you'll 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 available for it.