A CM website is slightly different from a Microsoft Internet Information Services (IIS) web site. While the rendered output of a CM website provides a total website experience for visitors to the site, a single CM website can actually be hosted on multiple web servers even though you are only maintaining a single website in your CM environment. Within the internal structure of IIS, a CM website is usually maintained as a subset of the iMIS application, but you can configure IIS to host CM websites as individual IIS applications or even as individual IIS web sites.
The following diagram illustrates the connection points between multiple IIS web servers that host CM websites, the iMIS database, and users.