In early days Microsoft had the legacy Command.com and cmd.exe as the shell access to administer Windows. They had their shortcomings, it didn’t give full capability to do everything from the cmd prompt which was allowed from the GUI . Later Microsoft introduced WSH with cscript.exe . This allowed much more flexibility for SA to administer systems. This integrated with Active Script Engine and allowed scripting in Jscript, Vbscript.

With the release of Windows Server 2003 Network Load Balancing has become a much more visible tool as a part of the operating system, providing a very usable and relatively easy to configure interface that makes it easy to build a Web Farm. The Network Load Balancing Service has been around in one incarnation or another since Windows NT SP4, but Windows Server 2003 is the first operating system that brings this service into the forefront as a main component of the OS.

You can host more than one website on a single web server using IIS. However, you must have a unique combination of host header name, IP address, and port number in order to do this. Let me try to explain to you what the host header is, how it works, and some common things most people don't understand about host headers.
HTTP message always includes the host header