Clip is commonly used as part of a video, a minute or so. Pretty much the same thing. A video is commonly used as anything recorded.
A video is more likely to be anything that contains moving pictures like the ones which you watch on social media platforms.
Footage is part of a video. Synonym for image image is a picture that does not move. Footage is commonly used on the news. |i suppose a gif could be called footage, but footage is usually used for something more serious.
Footage 和 video 和有什么不一样? a: