When you trim a video, it's basically removing the head and tail or starting point and ending point. Simply say, drag the trimming handles on each end to reduce the playback duration. On the other hand, cutting a video is to divide the video into two and remove the unwanted clip. Meanwhile, to split a video is to divide a video into multiple clips so you can edit them separately. Just think of it as extracting a scene in the middle of a long video. Lastly, splicing is to join two or more video clips after splitting.