DLL Hell; Manifests vs. Registration

[Jeff S]

I'm trying to more fully understand how .NET gets us out of dll hell by more
clearly understanding what goes into the manifest and contrasting that with
and what life was like before the manifest. Specifically, I would like to
know why COM components need to be registered in the Windows System
Registry. Registering COM components has been a fact of life that I've lived
with but never really understood or questioned. Now .NET is here and
registration is no longer required because.NET assemblies are
"self-describing" per the manifest. I can reasonably conclude that COM
components are not self-describing - and therefore need to be described by
something other than themselves. I'm presuming that "other thing" that
describes the component is the Registry (or type library - or both?). So,
with COM components (e.g., a simple "Hello World!" VB6 class compiled into
an ActiveX dll), what specifically needs to be described, and how does it
get described (what goes into the Registry, how do type libraries fit into
the picture)? It would be great if you could provide a comparison/contrast
with a .NET manifest (what goes into a .NET manifest - and where equivalent
info goes to describe a COM component) for a simple COM component and
equivalent .NET assembly.

Thanks in advance!