Debian is a well-known Linux distribution, which is used primarily on personal computers, but many people have started using it lately as a web server OS too, because of the stability and protection it offers. The latter is a result of the fact that Debian is developed and supported by thousands of qualified volunteers internationally, which means that any patch which is necessary to fix some issue is released within a couple of days. The same community can also help you with any question or trouble which a user may ever experience, because they can be contacted via electronic mail using e-mail lists and a qualified response will be sent in around 15-20 minutes. The advantage here is that all of your questions will be replied by the same people who have made the Operating System itself and they have an in-depth knowledge of how it functions. As Debian is absolutely free, you will not need to pay any license fees to use it and you can customize it as much as you want or need. This is valid for the Operating System and the 30.000+ software packages that are available for it.