Hairspray is a liquid product that you spray onto your hair to hold it in place. When you press the button on a hairspray can, a fine mist shoots out and coats your hair, then quickly dries into an invisible layer that keeps your hairstyle from falling apart.

People use hairspray when they want their hair to stay exactly how they styled it, whether that's keeping curls bouncy, holding a ponytail smooth, or maintaining a specific hairstyle for a special occasion like a school photo or performance. Athletes might use it to keep flyaway hairs out of their faces during competition. Actors and performers rely on hairspray so their hair looks the same throughout a show, even under hot stage lights.

The spray comes out of the can under pressure, which is why it makes that distinctive hissing sound. Before hairspray was invented in the 1940s, people used much stickier substances like sugar water or even beer to style their hair.