I know it's a way to record sound and maybe video (?) on a device smaller than a disc, but I have no idea what they look like.
Heh, you guys are funny. They don't "look like" anything because they're just a file format. It's a way of compressing sound by removing all but the most audible sounds. Maybe you're thinking of an MP3 player, which is an actual physical device that usually looks something like an iPhone. Which basically looks like a small square with a screen on the front.
Can't wait to get old and drive my grandkids crazy by mangling up all their language about virtual reality internet brain screen gaming neural network port newfangled thingmabobbers or whatever we have 60 years from now.