.NET Module vs Assembly

Question

I\'ve been trying to wrap my head around the \'right\' answer to this? there are a couple of topics on stackoverflow that covers this, but that conflicts somewhat with msdn

Answer 1

Every assembly has at least one module. It is an implementation detail that's highly invisible. But you can see it when you use Reflection.Emit. From the sample code for the AssemblyBuilder class:

AssemblyName aName = new AssemblyName("DynamicAssemblyExample");
AssemblyBuilder ab = 
    AppDomain.CurrentDomain.DefineDynamicAssembly(
        aName, 
        AssemblyBuilderAccess.RunAndSave);

// For a single-module assembly, the module name is usually
// the assembly name plus an extension.
ModuleBuilder mb = 
    ab.DefineDynamicModule(aName.Name, aName.Name + ".dll");

TypeBuilder tb = mb.DefineType(
    "MyDynamicType", 
     TypeAttributes.Public);

Note the use of the ModuleBuilder class, types are added to a module. That an assembly can contain multiple modules is pretty irrelevant, the build environment doesn't support it. Not just the IDE, MSBuild doesn't support it either. You'd have to write a build script yourself to use al.exe, the assembly linker. There are no good reasons to do this that I can think of, all .NET compilers already know how to generate a single module assembly directly. Al.exe is a typical bootstrapping tool, possibly used to build mscorlib.dll.