Thumbnail

In video and graphic design (as opposed to anatomy) a thumbnail is a small image used to represent a larger image or video file. For example, software that lets you manage a number of images often provides a miniaturized version of each image as a convenience feature for navigation. Similarly, many desktop video editing systems use thumbnail images to represent reels (files) of video footage. In this case there may be one thumbnail at the beginning of each file as displayed in the software system, or maybe many thumbnails, where they approximate the actual footage in the file, which makes it easier for the editor to grasp the full content of the file by making a quick visual scan of the track.