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
A module is a logical collection of code within an Assembly. You can have multiple modules inside an Assembly, and each module can be written in different .NET languages (VS, as far as I'm aware, doesn't support creation of multi-module assemblies).
Assemblies contain modules. Modules contain classes. Classes contain functions.
From: What is a module in .NET?
Really From: Bing search ".NET module vs assembly"