Manifest Maintains the information about the assemblies 
like version, name locale and an optional strong name that 
uniquely identifying the assembly. This manifest 
information is used by the CLR. The manifest also contains 
the security demands to verify this assembly. It also 
contains the names and hashes of all the files that make up 
the assembly. The .NET assembly manifest contains a 
cryptographic hash of different modules in the assembly. 
And when the assembly is loaded, the CLR recalculates the 
hash of the modules at hand, and compares it with the 
embeded hash. If the hash generated at runtime is different 
from that found in the manifest, .NET refuses to load the 
assembly and throws an exception.

Metadata means Data about the data.metadata yields the 
types available in that assembly, viz. classes, interfaces, 
enums, structs, etc., and their containing namespaces, the 
name of each type, its visibility/scope, its base class, 
the interfaces it implemented, its methods and their scope, 
and each method’s parameters, type’s properties, and so on. 
The assembly metada is generated by the high-level 
compilers automatically from the source files. The compiler 
embeds the metadata in the target output file, a dll, 
an .exe or a .netmodule in the case of multi-module 
assembly.

Assembly metadata is stored in Manifest. Manifest contains 
all the metadata needed to  do the following things.
Version of assembly
Security identity
Scope of the assembly
Resolve references to resources and classes.
The assembly manifest cdan be stored in either a PE file 
(an .exe or .dll) with Microsoft intermediate languages 
(MSIL) code or in stand-alone PE file that contains ony 
assembly manifest information.

Manifest contains Metadata(About Assembly).It consists of 
Name of the Assembly
Version of the Assembly
Scope of Assembly
Metadata is data about data.