The WebAssembly.Module object is the intermediate step between the ArrayBuffer and the instantiated module. The compile() and instantiate() methods (and their streaming counterparts) return a Promise that resolves with a module (module in lowercase represents the compiled Module). A module can also be created synchronously by passing a typed array or ArrayBuffer directly into the constructor, but this is discouraged for large modules.

The Module object also has three static methods: exports(), imports(), and customSections(). All three take a module as a parameter, but customSections() takes a string representing the section name as its second parameter. Custom sections are described in the Binary Format section of the Core Specification and are intended to be used for debugging information or third-party extensions. In most cases, you won't need to define these. The exports() function is useful if you're using a Wasm module that you didn't create, although you'll only be able to see the name and kind (for example, function) of each export.

For simple use cases, you won't be dealing directly with the Module object or compiled module. Most of the interaction will take place with an Instance.