"Glow in the dark" refers to materials that emit light after being charged by a light source. These materials contain phosphors, which absorb energy and then release it slowly, creating a glowing effect in the dark. Common applications include toys, watch dials, and safety signs. The glow typically lasts for a limited time, depending on the material and the intensity of the light source used for charging. Popular examples of glow-in-the-dark products include stars for ceilings, stickers, and paint. These items are often used for decoration or to enhance visibility in low-light conditions.