Web hosting is the leasing of web server resources for the purpose delivering website, blog, or eCommerce content to visitors.
In most cases, you'll need to acquire your own web hosting services if you're planning on creating a website, blog, or self hosted eCommerce solution.
Typcially each web host offers at least 3 different tiers of hosting services: Shared Hosting plans, Dedicated Hosting plans, or Cloud Hosting plans.
With Shared Hosting your website is one of several websites hosted on a server.
The server resources are limited, and shared with all websites hosted on that server. The benefits include a broad array of functionality included such as e-mail inboxes, and one click component installations.
Dedicated Hosting plans are plans in which the service provider leases an entire server over which the customer has varying levels of control. Management and administrative services for the server may also be provided by the service provider, often times at an additional cost.
Cloud hosting services are similar in many ways to dedicated hosting. The primary differences being that cloud hosting services emphasize the ability to accomodate massive volumes of traffic, all while maintaining high security and continuous availability.
What follows is a summary of what to actually expect when purchasing dedicated hosting or shared web hosting options.
Web hosting providers love to boast uptimes of 99.8% or 99.9%. What many consumers don't realize is that these numbers do not include scheduled maintenance.
Although it may not seem like it, the difference between 99.8% and 99.9% uptime is huge. An uptime of 99.9% would mean that each year, your website will be unavailable for 8 hours and 45 minutes; whereas an uptime of 99.8% would mean your website is unavailable for 17 hours and 30 minutes!
In this case, a mere one tenth of 1 percent (.1%) decrease in uptime actually doubles the amount of time your website will be unavailable!
Web hosting providers often claim to offer unlimited disk space, or unlimited bandwidth as selling points. Really, in stating this, what they mean is "we have all the resources you should need".
Web hosts also state that they reserve the right to take your website offline if it degrades the performance of their network or their servers. This is particularly true for shared web hosting, as these servers often host several websites - sometimes 100s of them!
It is fair to say that over a long enough time frame there may be no limitations on bandwidth usage, disk space usage, CPU usage, or RAM usage. I can assure you though, at any given moment there are limitations in place on your web hosting account.
For a more detailed explanation of why shared web hosting services or dedicated web hosting services are never truly unlimited, take a look at The Pipe Example from techtites.com. The analogy and accompanying explanation is very informative.
Unless you are going to hire a consultant to develop your company's website, ultimately the operating system your web host uses will be of little consequence.
Many of the technologies used in web developement today, including WordPress, Joomla, and Drupal, work on both Windows and Linux server operating systems.