Debian is a well-known Linux release, that's used mainly on desktop machines, but 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 consequence of the fact that Debian is developed and supported by a large number of qualified volunteers worldwide, which means that any patch which is necessary to fix a particular issue is released in a couple of days. The very same community will also help with any question or problem that a user may ever have, as they can be contacted through e-mail using mailing lists and a competent response will be sent in no more than 15-20 min. The advantage here is that all 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 free, you will not have to pay any license fees to use it and you will be able to personalize it as much as you want or need. This is valid for the Operating System as well as the 30.000+ software packages that are readily available for it.