A light source is any object or device that emits light, making it visible to the human eye. Common examples include the Sun, light bulbs, and fire. Light sources can be natural, like the Moon reflecting sunlight, or artificial, such as fluorescent or LED lights used in homes and streets. Light sources can be classified into two main categories: incandescent and non-incandescent. Incandescent sources produce light by heating a material, like a traditional light bulb, while non-incandescent sources, such as lasers and neon lights, generate light through different processes. Each type has unique applications and characteristics.