Reels is Instagram's short-form video platform that launched to little fanfare, but has bolstered the app's growth over time.CHRIS DELMAS/AFP via Getty ImagesInstagram launched Reels a few years ago, its own short-form video platform to compete with TikTok.Users can watch reels on Instagram's Reels tab, Explore page, and in their own feeds.Instagram later announced it would publish virtually all video posts under 15 minutes as reels.