What's the difference between ImageSR and VideoSR?

The NGX sdk has 2 super resolution components, ImageSR and VideoSR,so what’s the difference between them? Can I use ImageSR on video? after all,video is a sequence of images.

VideoSR 1080p is like 23fps on 2080ti (Still too slow for real-time)

Image SR is like 2fps but better quality.