Server-side routing involves the server processing all routing tasks. When a user clicks on a link or makes a request, the request is sent to the server. The server then interprets this request and decides what data to send back to the client. It generates the appropriate view on the server and sends it back to the client as a fully rendered HTML page.
This can make the initial rendering of the page slower because the entire page needs to be prepared on the server and then sent over the network to the client. However, it can be beneficial for SEO purposes since search engines can crawl the site more easily.