Aerosol cans are containers that hold liquids under pressure, allowing for the spray or misting of their contents when a valve is opened. They are commonly used for products like hairspray, deodorant, and cleaning supplies. The can's design includes a nozzle that releases the product in a fine mist, making it easy to apply. The contents of aerosol cans are typically a mixture of a liquid product and a propellant, which helps to expel the liquid when the can is pressed. Proper disposal is important, as many aerosol cans are made of metal and can be recycled, but they must be empty and punctured to ensure safety.