A GIF (or graphic interchange-able format) is a collection of images, often taken from a video file, and broken down into a low-quality flicker book looking image, which portrays 1-4 seconds of video. Usually, only the key moments/frames are shown, typically around 8 frames per second. In no way does a GIF attempt to recreate, or supersede video, it usually focuses around a key moment from a video, and disregards events leading up to and following it. A GIF is also repetitive by nature, and will infinitely repeat.
It creates a more fragmented narrative, borrowing elements from both photography and video. The lack of sound makes the visuals take on a different meaning, in a sense taking it one step from reality, and more into a stylised format.