Earlier on in the book, we had emphasized that large-scale JavaScript applications are just collections of components. These components communicate with one another in complex and intricate ways—these communications are what realize the behavior of our system. Before components can communicate, they have to be delivered to the browser. It's helpful in understanding what these components are made of, and how they're actually delivered to the browser. Then we can reason about the initial load time of our application.
Components are the bedrocks of our application; that means we need to deliver them to the browser, and execute them in some coherent manner. The components themselves can range from being monolithic JavaScript files, to something that's spread out over several modules. All the puzzle pieces are put together through the dependency graph. We start off with an application component, as this is the entry point into our application. It finds...