A web host is not just a web host. Different web hosts offer different technologies and different types of hosting. Which technology and type of service fits your website needs depends on many factors.
Here's a secret. If you use an experienced website designer to design your website, trust their recommendations in web hosts. Most designers who have been in business for 3 or more years have extensive experience with web hosts.
One important consideration is not only the needs of your website today, but future plans for the site. This is an important question every web developer should ask, but if they don't - make sure you tell them (or find someone who is forward thinking and concerned about your over all objectives).
Also be aware that the best in web hosts can turn bad almost overnight if bought out by a larger company that doesn't pay attention to customer service. It isn't always that a bad choice was made in web hosts; sometimes it can be that a good host turns bad.
Huge hosting companies have the revenue to have the latest technology, but often may not offer the same level of customer service. Small web hosting companies may lack in resources, the latest technlogy and may have limited customer support.
Web servers are operated just like your computer in the sense that each is controlled by the operating system it runs.
The operating system on your web host determines the types of programs that it can offer for your use.
There are three main web host operating systems:
Linux and Unix servers offer approximately the same technology and therefore are sometimes referred to together as __X servers.
Linux is not really an operating system in itself. It is a "kernal" that controls hardward and drivers. GNU is the operating system software behind Linux. Interestingly enough and confusing is that GNU stands for "GNU's Not Unix ".
However most servers running GNU and Linux Kernal simply call the system Linux. Both are open source softwares, meaning free technology to those who want to use it.
Often Linux web hosting can be less expensive because the operating system and many of the technologies (PHP, MySQL) that it runs are open source. However, some hosts using open source technology also skimp on control panels. A good, intuative control panel can save lots of time and prevent questions.
Linux is known for speed. It's a light and mean, making it fast. But as with any open source software (some more than others) the documentation behind Linux may not be as user friendly or complete as a system generating consistent revenues
Do remember that it's much easier to begin a hosting service using Linux because it requires less investment. While that may translate to cheaper web hosting prices, it may also translate to inexperience and "easy in, easy out" type of businesses. Of course all hosts running Linux should not be suspect. Rather, make checking the number of years in business one of your criteria.
Like Linux, UNIX servers run open source technology such as PHP and MySQL. The UNIX operating system was developed by AT&T in the late 1960's. It has a higher hardware requirement than Linux. However the Linux system is based on UNIX. UNIX is known for better security and is also an Open Source operating system software.
The windows operating system on servers is comparable but more robust than that which runs on the normal PC.
Windows servers run ColdFuision, ASP, ASP.net Access and MS SQL.
However some web hosts run additional software that can made a Windows server emulate a UNIX type system, allowing open source programs such as PHP, Apache and other open source technologies to run well on it.
Because the windows operating system costs, hosting accounts running Windows usually are more expensive than Unix and Linux systems. One of the complaints about the Windows OS is that hosting companies never know what their costs will be from year to year. Microsoft does not offer price guarantees to their Licensees.