IIS - what we need to know

IIS is a listening mechanism for incoming requests. The basic entity in IIS we should know of is the IIS Website; requests can get mapped to a particular website based on certain criteria - port number (like 80, 8089), ip address and/0r host header (http://www.blogger.com). Now this website will also be mapped to a physical address (a directory in the server - c:\inetput\myroot) which can have files inside that can throw out html (abc.htm, default.aspx). so that is how html gets displayed when we go to a particular page in iis hosted website

Beyond this, what does IIS help in
1. Authentication - You can set authentication (windows, basic or no auth) to your website seamlessly without you writing code
2. configure logs etc.,

now all these configurations for your website needs to be stored somewhere, right that is the iis metabase. you can find the file here on your webserver %SystemRoot%\System32\Inetsrv

Beyond this, something we need not know is about isapi extensions and isapi filters.