What is "newsreels"

Usage examples of "newsreels".

The vast slush-covered expanse, where sometimes the self-aggrandising parades beat hell out of the road surface for newsreels, was on that day trodden only by miserable-looking groups of tourists, shepherded in straggling crocodiles to and from a group of buses parked nearby.

Otherwise you see it only later, in newsreels, or else in films made long after the event.