Debian is a widespread Linux distribution, that is used primarily on personal computers, but many people have begun using it lately as a web server OS too, because of the stability and protection it offers. The latter is a direct result the fact that Debian is developed and supported by a large number of qualified volunteers internationally, so that any patch which is needed to fix some issue is released within a couple of days. The very same community will also help you with any question or issue which a user may ever encounter, since they can be contacted via electronic mail using mailing lists and a competent response will be sent in around 15-20 minutes. The advantage here is that all your queries will be responded to by the same people who have made the Operating System itself and they have a detailed knowledge of how it functions. As Debian is free, you will not have to pay any kind of license fees to use it and you will be able to personalize it as much as you want or need. This is valid for both the Operating System and the 30.000+ software packages which are available for it.