Debian is a well-known Linux distribution, which is used mainly on desktop computers, still numerous people have begun using it lately as a web server Operating System too, because of the stability and security it offers. The latter is a result of the fact that Debian is developed and supported by countless qualified volunteers internationally, so any patch which is required to fix a particular issue is released in a matter of days. The very same community will also help you with any question or trouble which a user may ever have, due to the fact that they can be contacted via electronic mail using mailing lists and a competent response will be sent in no more than 15-20 minutes. The advantage here is that all of your questions will be answered 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 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 both the Operating System as well as the 30.000+ software packages that are available for it.