Shorts & Vertical Video
Cut
Also called: Shorts Cut, sample a clip
Cut sits in the Shorts creation tools next to Sound, Green Screen and Collab. It lifts a segment of one to five seconds from another YouTube video, taking both the picture and the audio, and drops it into your own Short, most often as the setup for a reply or a reaction.
The source gets credited in the Shorts player with a link back to it, which is why some creators deliberately leave remixing switched on. Availability has holes in it. Private videos are out, so are videos whose copyright owner has not cleared remixing, and any creator can turn remixing off on their own uploads.