Light activation refers to the process where light energy triggers a specific reaction or change in a material or biological system. This phenomenon is commonly observed in photosynthesis, where plants use sunlight to convert carbon dioxide and water into glucose and oxygen. In technology, light activation is utilized in various applications, such as in phototherapy for treating skin conditions or in photovoltaic cells that convert sunlight into electricity. These processes rely on the interaction between light and matter to produce desired effects, showcasing the importance of light in both nature and technology.