What is purpose of Assembly Linker or define SDK Tool in .NET Framework?

In .NET whole the working should be with the helps of DLLs.So all of Visual Studio .Net compilers gernate assemblies or u can say dll.If we want to create an assembly with manifest of a module.We can also put this assembly in seprate file.This AL tol gernate a file with an assembly manifest from modules or resources fles.The syntax of using Al.exe is   al [sources] [options]
This tool helps in creating multi-file assembly outside Visual Studio .Net .This multi file can contain modules that are written in diffrenet langauage in one application.