Emscripten's official site provides the following definition for the Module object:
"Module is a global JavaScript object with attributes that Emscripten-generated code calls at various points in its execution."
Not only is the loading procedure different from WebAssembly's compile and instantiate functions, but the Module provides some helpful functionality out of the box that would otherwise require a custom implementation in WebAssembly. The Module is available in a global scope (window.Module) after fetching and loading Emscripten's JavaScript glue code.