To quote Microsoft, "Assemblies are the building blocks of the .NET Framework."
An assembly is composed of four sections.
The first is the assembly manifest.
The manifest contains information about the assembly itself.
The manifest includes such things as the name of the assembly, its version number, type mapping information, and cultural settings.
The second section is type metadata
The type metadata is information about the data types.
The type metadata aids in cross-language interoperability.
The third part of an assembly is the program code stored in Microsoft Intermediate Language (MSIL) format.
The fourth constituent of an assembly is the resources used by the program.
