TypeScript is rad. Here's a first hand experience about why the Delve engineering team is all about TypeScript. hint: TypeScript forces them to fall into the Pit of Success more than all of their other infrastructure combined. If you're wanting to see why TypeScript might be a great addition to your engineering team, check out this article.
Zones are an abstraction allowing you to write cleaner code for a variety of purposes, including implementing server-side rendered (SSR) applications, profiling, more useful stack traces for debugging, or a clean way to implement dirty checking.
Unit tests, integration tests, and functional tests are all types of automated tests which form essential cornerstones of continuous delivery, a development methodology that allows you to safely ship changes to production in days or hours rather than months or years.
Web rendering is rather useful during the front-end development because, as you can understand, markup, styles and scripts are very important so why not learn some lifehacks? This article is not aimed at describing the accurate mechanics of work browsers, but rather on understanding its general principles.