They mean not having to write any client-side JS. So, having a mechanism to use the backend language for both the content that gets displayed when the page/comp

They mean not having to write any client-side JS. So, having a mechanism to use the backend language for both the content that gets displayed when the page/component first loads AND any interactivity thereafter. It’s easy to populate a <select> with values with (traditional) SSR, but then you’d often have to write some JS to make additional requests when the user makes a selection, for example. Seems weird to me to use “SSR” as a term for both SSR + hydration, but I’m not in the web dev lingo bubble so what do I know? The author doesn’t use the term “hydration” until the blurb at the end talking about Quik