From Thom Robbins blog:
http://blogs.msdn.com/trobbins/articles/404939.aspx

<cite>
It is important to remember that metadata describes the contents of the
assembly, whereas the Assembly manifest describes the assembly itself.
</cite>

This makes a nice distinction, but, by definition, metadata is data about
data (or data about a program). Metadata is the portion of a program that is
hidden from the user, as it is not important what the answer is, not what
bits combine to get an answer. From the definition, therefore, the manifest
would contain metadata about an assembly.

Think of the manifest as the type library of a .NET assembly. It contains
information about the assembly so the developer can use the assembly in his
code. This is a bit oversimplified, but it gets the point across.

Follow this link http://blogs.wwwcoder.com/govinda/archive/2004/08/02/635.aspx
--Rama--