SPA architecture

In this section, we will start to understand the single-page application (SPA) architecture.

A SPA is a web app that loads a single HTML page that is dynamically updated by JavaScript as the user interacts with the app. Imagine a simple sign-up form where a user can enter a name and an email address. When the user fills out and submits the form, a whole page refresh doesn't occur. Instead, some JavaScript in the browser handles the form submission with an HTTP POST request and then updates the page with the result of the request. Refer to the following diagram:

Figure 1.1 – Form in a SPA

So, after the first HTTP request that returns the single HTML page, subsequent HTTP requests are only for data and not HTML markup. All the pages are rendered in the client's browser by JavaScript.

So, how are different pages with different URL paths handled? For example, if I enter https://qanda...