Joining a web development community can be a challenge within itself, especially when all the resources you visit assume you're familiar with other technologies that you're not familiar with.
Our goal is to help you avoid that mess and come up to speed as fast as possible; you can consider us your internet friend.
Content Delivery Network
This is typically a paid service you can use to get great performance for your app. Many CDNs act as caching proxies to your origin server; some require you to upload your assets to them. They give you a URL for each resource in your app. This URL will resolve differently for folks depending on where they're browsing.
Behind the scenes, the CDN will distribute your content geographically with the goal of end-users being able to fetch your content with the lowest latency possible. For example, if a user is in India, they'd likely get content served from India faster than from the United States.
Browsers that update themselves (without user intervention).
Most browsers support at least ES5, and some even have ES6 (also known as ES2015) support. You can check each browser's support (including yours) here:
Both LESS and Sass are types of CSS preprocessor markup intended to give you much more control over your CSS. During the build process, the LESS or Sass resources compile down to vanilla CSS (which can be executed in a browser).
Asynchronous calls typically return a promise (or deferred). This is an object which has a state: it can be given handlers for when it's fulfilled or rejected.
Ember makes use of these in places like the model hook for a route. Until the promise resolves, Ember is able to put the route into a "loading" state.
Not to be confused with Virtual DOM. Shadow DOM is still a work in progress, but basically a proposed way to have an "isolated" DOM encapsulated within your app's DOM.
Creating a re-usable "widget" or control might be a good use-case for this. Browsers implement some of their controls using their own version of a shadow DOM.
Not to be confused with Shadow DOM. The concept of a virtual DOM means abstracting your code (or in our case, Ember) away from using the browser's DOM in favor of a "virtual" DOM that can easily be accessed for read/writes or even serialized.