Apple uses their HTTP Live Streaming system for this. It is essentially a refreshing m3u playlist of 10 second MP4 video chunks that are served as normal files

Apple uses their HTTP Live Streaming system for this. It is essentially a refreshing m3u playlist of 10 second MP4 video chunks that are served as normal files via HTTP, over their standard CDN. It works well as long as the playlist refreshes properly, and the data gets deployed to the CDN fast enough.