Single Page App (SPA)
A single-page application and will refer to as (SPA) is an app that works inside a browser and does not require page reloading during use. You are using this type of applications every day. These are, for instance: Gmail, Google Maps, Facebook or GitHub.
Multiple Page App (MPA)
Multiple-page applications and will refer to as (MPA) work in a “traditional” way. Every change eg. display the data or submit data back to server requests rendering a new page from the server in the browser. These applications are large, bigger than SPAs because they need to be. Due to the amount of content, these applications have many levels of UI. Luckily, it’s not a problem anymore. Thanks to AJAX, we don’t have to worry that big and complex applications have to transfer a lot of data between server and browser. That solution improves and it allows to refresh only particular parts of the application. On the other hand, it adds more complexity and it is more difficult to develop than a single-page application.
You need to consider the goal of the site and who you are targeting overall. If you know you need multiple categories (because, for instance, you run an online shop or publish a lot of other content) — use a multi-page site. If you are sure that your site is appropriate for a pure single-page experience — go for it. And if you like SPA but can just barely fit everything into a single page, consider the hybrid site instead. This is another way I haven’t mentioned before. A hybrid application takes what is the best in both approaches and try to minimize the disadvantages. It is, in fact, a single page application which uses URL anchors as synthetic pages enabling more in build browser navigation and preference functionality. But this is the topic for another article.
Possibly in the near future, everyone will use Single Page Application model (including a hybrid app), as it seems to bring a lot of advantages. Many apps on the market are migrating towards this model. However, as some projects simply cannot fit into SPA, the MPA model is still vivid.