These, as well as the ones cited in the next comment down, are all file extensions only developers or perhaps power users would know. But .zip is a very mainstr

These, as well as the ones cited in the next comment down, are all file extensions only developers or perhaps power users would know. But .zip is a very mainstream file extension, perhaps one of the most mainstream ones besides the media ones (mp3, mp4, jpg, png, gif) and .exe.