Debian is a popular Linux distribution, which is used mainly on desktop machines, however numerous people have started using it lately as a web server Operating System as well, due to the stability and security it provides. The latter is a direct result the fact that Debian is developed and supported by numerous qualified volunteers internationally, which means that any patch which is necessary to fix a particular issue is released within a few days. The same community can also help you with any question or problem that a user may ever encounter, due to the fact that they can be contacted through electronic mail using mailing lists and a qualified response will be sent in around 15-20 min. The advantage here is that your queries will be replied by the same people who have made the Operating System itself and they have an in-depth knowledge of how it works. As Debian is free, you won't have to pay any license fees to use it and you can personalize 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.