A JavaScript module encapsulates code into a useful unit that exports its
capability/value. This makes it easier to see the broader scope, easier to find
what you’re looking for, and keeps related code close together. A normal web
page usually loads JavaScript files via HTML script tags. That’s fine for
small websites, but when developing large scale web applications, a more robust
organization and loader is needed. A module loader lets an application load
dependencies easily by specifying a string that identifies the JavaScript
module’s name.
These tutorials show you how to load JavaScript modules in Portal.