JavaScript modules allow a program to be divided into multiple sequences of statements and declarations. Each module explicitly identifies declarations it uses that need to be provided by other modules and which of its declarations are available for use by other modules. <script type=module> allows loading of JavaScript modules inside web pages.
Docs: https://blog.whatwg.org/js-modules http://tc39.github.io/ecma262/#sec-modules https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script https://jakearchibald.com/2017/es-modules-in-browsers/