It’s been always the same. Backend, server logic, database… dynamic content; on one hand. JavaScript runs on the browser for almost anything, sometimes for dynamic content. But it’s not tied. You could have an in-browser button with a counter for the numbers of times it was pressed (that’s actually an entry-level programmer exercise) and that’s a static site. If you saved the counter value to the server (e.g. database) then it’s not static anymore.