What is a Manifest? 

An assembly manifest have all the metadata needed to specify the assembly's version requirements and security identity, and all metadata required to define the scope of the assembly and resolve references to resources and classes. The assembly manifest can be stored in either a PE (Portable Executable) file (an .exe or .dll) with Microsoft intermediate language (MSIL) code or in a standalone PE (Portable Executable) file that have only assembly manifest information. The following table shows the information contained in the assembly manifest. The first four items - the assembly name, version number, culture, and strong name information - make up the assembly's identity.

Assembly name: A text string specifying the assembly's name. Version number: A major and minor version number, and a revision and build number. The common language runtime uses these numbers to implement version policy.

Culture: Information on the culture or language the assembly supports. This information should be used only to designate an assembly as a satellite assembly having culture- or language-specific information. (An assembly with culture information is automatically supposed to be a satellite assembly.) Strong name information: The public key from the publisher if the assembly has been given a strong name. List of all files in  the assembly: A hash of each file contained in the assembly and a file name. Note that all files that make up the assembly must be in the similar directory as the file containing the assembly manifest. Type reference information: Information used by the runtime to map a type reference to the file that have its declaration and implementation. This is used for types that are exported from the assembly.