Frames

Filter the list. With JS on, only the framed region swaps (the response is just the frame's subtree, not the whole page) and the heading above never re-renders. With JS off, the same links do full-page navigations. It is one region refreshing independently of a navigation, which neither a page nor a layout can express: a layout wraps routes with shared chrome and only re-renders when you navigate, while a frame updates one region in place.

A frame can also self-load with src (loading="lazy" defers the fetch to viewport entry), or be driven from outside via data-webjs-frame="tasks". data-webjs-frame="_top" breaks out to a full-page navigation.