Modern JavaScript applications implement a pattern known as an SPA. In its most simplistic form, it can be thought of as an application that displays components based on a URL. As the templates are mapped to routes, there is no need for a page reload, as they can be injected depending on where the user navigated.
This is the job of the router.
By creating our application this way, we're able to increase both perceived and actual speed, because our application is much more dynamic. If we add in the concepts that we learned in the previous chapter (HTTP), you'll find that they go hand in hand with the SPA model.
