How to create a new module

Hi, I am learning to program apps with ionic. There are a few things I don’t understand at the moment:
In angularJS you can create a module by “angular.module(“name”, [])” and then set a controller by ".controller(“ctrl”, function($scope){

})"

First of all: Where do I create such a module in my Ionic project?
2. How can I gain access to the module in another .ts file
3. Is there a big difference between declaring a module in Javascript and in Typescript?

I am sorry if some of the questions are stupid…
Thanks for helping!

Have a look at this: https://angular.io/tutorial
This will help you get started with Angular (which is used by Ionic) and forget about the AngularJS stuff.