Gelatin is a clear, flavorless substance that turns liquid into a soft, jiggly solid when it cools. You've probably seen it in Jell-O, gummy bears, marshmallows, and many other foods.

Gelatin comes from collagen, a protein found in animal bones and skin. When manufacturers boil these parts in water, the collagen dissolves and becomes gelatin. After drying into a powder, it can be mixed with hot liquid, which sets into that familiar wobbly texture as it cools.

Gelatin works through an interesting chemical process: its long protein molecules form a network that traps water molecules, creating a structure that's solid enough to hold its shape but soft enough to jiggle. This same property makes gelatin useful beyond desserts. Photographers once used gelatin in film to hold light-sensitive chemicals. Pharmacists use gelatin capsules to hold medicine. Chefs use unflavored gelatin to thicken sauces or make panna cotta, a creamy Italian dessert.

The word gelatinous describes anything with that signature jiggly, semi-solid texture, whether it's a jellyfish drifting through the ocean or a wobbly dessert on your plate.