Debian is a popular Linux release, that is used mainly on personal computers, however lots of people have begun using it lately as a web server Operating System as well, due to the stability and security it supplies. The latter is a consequence of the fact that Debian is developed and supported by countless qualified volunteers all around the world, so any patch that is needed to fix a particular issue is released within a matter of days. The same community can also help you with any question or problem which a user may ever have, since they can be contacted through email using mailing lists and a competent response will be sent in around 15-20 minutes. The advantage here is that all your questions will be replied by the same people who have designed 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 customize 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.