The document discusses component-oriented architecture in Angular 2. It defines components as the basic building blocks of an Angular 2 application. Components contain HTML, CSS, and JavaScript. There are two types of components: presentational/dumb components and container/smart components. The document outlines how components interact with each other through property binding, event binding, and two-way binding. It provides an example of how different reusable components like navbar, search, product, and footer can be composed to create an online auction site.