Using the File API, web content can ask the user to select local files and then read the contents of those files. This selection can be done by either using an HTML element or by drag and drop.| MDN Web Docs
An important aspect of custom elements is encapsulation, because a custom element, by definition, is a piece of reusable functionality: it might be dropped into any web page and be expected to work. So it's important that code running in the page should not be able to accidentally break a custom element by modifying its internal implementation. Shadow DOM enables you to attach a DOM tree to an element, and have the internals of this tree hidden from JavaScript and CSS running in the page.| MDN Web Docs
elements with type="file" let the user choose one or more files from their device storage. Once chosen, the files can be uploaded to a server using form submission, or manipulated using JavaScript code and the File API.| MDN Web Docs
One of the key features of web components is the ability to create custom elements: that is, HTML elements whose behavior is defined by the web developer, that extend the set of elements available in the browser.| MDN Web Docs
HTML| html.spec.whatwg.org
The is the most versatile and used element in HTML. It represents nothing, while allowing developers to manipulate it into almost anything by use...| www.scottohara.me
Finally! A way to yell at your computer and have it actually listen.| thoughtbot