Hello sentmemail,
As I see you ask the same question in two successive threads, I might as well venture into something which I constantly being humbled because it is so vaste a subject to know in substance rather than in name. So a little lead may at least serve as a tiny step for further research.
Internet Explorer by its own is based on two components: the WebBrowser Control (SHDOCVW.dll) and MSHTML.dll. The latter is the parsing and rendering engine whereas the former expose controls which are used as well by desktop and others system services. Shdocvw.dll is also something separated from older Shdoc__ as a independent realization of some functionality. That is also why we hear so often that IE is so much integrated into the system and have a material repercussion on the os if different IE version is installed.
Not much in substance, but no one can replace bumpy readings and practice on one's own effort.
regards - tsuji