Your browser assumes that the server is reachable on port 80 if you are browsing a http site or port 443 if you are using https. The server mentioned above runs on port 8080. So the Browser needs this information which is then added to the url

It means they are running the server on port 8080, which is actually a popular choice if port 80 is already in use or if you don't want to access a "privileged port" in Unix.

I would have thought 8443 was a more common choice for HTTPS on a unprivileged port rather than 8080, which is frequently used for unprivileged HTTP. But it matters little, its only cosmetics anyway.