Phosphorescent materials are substances that can absorb light and then re-emit it over time. This process occurs when the material captures energy from a light source, such as sunlight or artificial light, and stores it. When the light source is removed, the material gradually releases the stored energy as visible light, creating a glow that can last from seconds to hours. Common examples of phosphorescent materials include certain types of glow-in-the-dark paints and zinc sulfide crystals. These materials are often used in safety signs, toys, and decorative items, providing illumination in dark environments without needing a continuous power source.