The way that single page applications bring these benefits is linked to the way that they work internally:
The key point to understand how single page applications work is the following:
instead of converting data to HTML on the server and then send it over the wire, in a SPA we have now moved that conversion process from the server to the client.
The conversion happens last second on the client side, which allow us to give a much improved user experience to the user.
In a SPA after application startup, the data to HTML transformation process has been moved from the server to the client – SPAs have the equivalent of a template engine running in your browser!