What is a Single Page Application (SPA)?

-: Now as I said, in this course we'll build a single page application with Angular. Now, what is that? What is a single page application? Well, in an Angular app, we'll have one root html file. A so-called index html file. And we will serve that from our node server or a different server. That's important. It can be totally decoupled of our node back end. And it actually will be. And this html page basically includes some script imports that houses our Angular App. So the Angular framework and our own code. And we use that application to dynamically re-render what the user sees without ever requesting a second page to be rendered by the server. Why? Because by having this pattern, we never need to reload the page just because the user maybe clicked on a post and wanted to see the details. We can instead navigate to that page directly because we don't really leave the page. We just remove some elements from the DOM and add new elements. And all of that is handled for us by the Angular framework. It's really convenient to use and to work with the DOM with it. And therefore, we have a powerful way of immediately changing the page. Maybe showing a spinner while it's refreshing some data behind the scenes. So that list of posts, which we probably still need to get. But we will do that behind the scenes. And this provides a highly interactive mobile app-like feeling. A very responsive and fast webpage where we never have to wait. Where things always happen. And that of course, is a great user experience. And this is why we will use JavaScript in Angular. Therefore, for the entire front end. For the entire user interface. And we will use Node Express and Long ODB as a back end to which we reach out behind the scenes to fetch data and send data. But the whole user interface is handled as one page only which is dynamically re-rendered all the time by Angular.