1) Client Operating Systems
2) Server Operating Systems.
Client Operating Systems:
Client operating systems are capable to provide a nice user interface to the user to interact with hardware. Some examples are DOS(which is a CUI based OS), Windows family Operating Systems (like Windows 9x family, windows XP, Windows 7, Vista etc) .
Server Operating Systems:
Server Operating systems provide the exact functionality that the client OS provide, In addition They can:
1) Handle Tera bytes of Storage disks.
2) Running a Webserver like Softwares.
3) Capable of running on a Multi Processor Environment
4) Improved Security etc..
The above are some of the main functionalities of a Server OS. Most populare Server OS’s are : Unix, Linux and Windows NT Family Server OS, Solaris etc.
The Concept:
So whenever you type a URL in a browser (Firefox, IE or chrome etc), the request will go to the Webserver, which was running on a Server OS.
Consider you request the site www.asp.net which is a ASP technology site (that is build on ASP.Net Technology), So your request directly sent to Windows Server.
Because, Microsoft created the ASP.Net Technology which is a web development technology, which can be run inside the IIS web server (which is also a Microsoft product). So whenever a ASP page kept under the IIS server and its ready for client’s request.
So that only I previously told, whenever you request a ASP.Net (.aspx) page it was kept under the IIS and served to Client.