As mentioned before, Angular represents a full rewrite of the AngularJS framework, introducing a brand new application architecture completely built from scratch in TypeScript, a strict superset of JavaScript that adds optional static typing and support for interfaces and decorators.

In a nutshell, Angular applications are based on an architecture design that comprises of trees of web components interconnected by their own particular I/O interface. Each component takes advantage under the covers of a completely revamped dependency injection mechanism.

To be fair, this is a simplistic description of what Angular really is. However, the simplest project ever made in Angular is cut out by these definition traits. We will focus on learning how to build interoperable components and manage dependency injection in the next chapters, before moving on to routing, web forms, and HTTP communication. This also explains why we will not make explicit references to AngularJS throughout the book. Obviously, it makes no sense to waste time and pages referring to something that will not provide any useful insights on the topic, besides the fact we assume that you might not know about Angular 1.x, so such knowledge does not have any value here.