Lately you've probably heard of contradictions about the best web host. I refer to the operating system used, Windows and Linux. There are people who think Windows web hosting is better but often it depends on what their web site needs.
You still need to know that these two operating systems are not the only ones used for web hosting, so I’ll try to describe in few words the main operating systems that a web host can use:

1) Windows. The most common and popular operating system used at this time. It is used very often for web hosting as it offers a highly diversified support and also because most users are familiar with it. Windows web hosting is an offer you need to take seriously into consideration when looking for a high quality web host.

2) Linux. It is one of the most popular operating systems and when it comes to web host is very popular because it's free and when problems occurred on a Linux web hosting can be solved very easily.

3) Unix. Even if it looks very much like Linux is not used very much in web hosting because is costly and requires high attention from many points of view.

4) Macintosh. You can hardly find a web host that is using Macintosh due to the high cost that such a server requires.

      As I said Windows and Linux web hosting are the most common solutions for web hosts operating systems.Between them there are differences that make some users prefer Windows web hosting and others not.
For example, to access files on a Windows or Linux web server you can use FTP access.Besides FTP, Linux still comes with other solutions such as SSH and Telnet access.

With FTP access on the server you can transfer files from your own hard drive while Telnet and SSH allows editing files in a window directly on the web server.
     Regarding the supported programming languages I can tell Windows Web Hosting has a little advantage from Linux because the second has some deficiencies with FrontPage extensions.
     From the security point of view of both,Windows and Linux offer full service web hosting security but all of that depends on administrators and their experience.
Differences between Windows web hosting and Linux web hosting are very small and therefore usually depends on you to choose the best solution when looking for a reliable web host.