While we don't want to get too technical, here are the main differences between GIF and MP4.
- MP4 can contain audio while GIF cannot
- GIFs are larger in file size when dealing with bigger resolutions and longer durations vs MP4s
- GIFs use a reduced 256 color palette, which makes GIFs look more grainy on realistic images
- Any browser this century can natively support GIFs, while HTML5 is needed to natively support MP4