What does light source mean?
A light source is an object that emits light. There are different types of sources that emit light. These can be created by humans, for example, LED interior lighting. This is an example of an artificial light source. But there are also natural light sources. These are not created by humans, for example, the sun. In both cases, light is produced by atoms that contain a lot of energy.
What does it consist of?
We need light to see. Without a light source, we see nothing. The light around us enters the eye, is converted into signals and sent to the brain to create an image. But what is it made up of? All matter around us is made up of atoms. Atoms are the smallest particles of matter that exist. But atoms are made up of even smaller particles. In atoms, electrons represent all kinds of orbits in an electron cloud. We can interfere with the motion of these electrons in various ways, such as by heating the atom. The electrons then spin in different orbits around the nucleus. They become excited. But they "want" to return to their old orbit. The moment it rebounds, it emits a flash of light. This is also called a photon.
Direct and indirect light sources, what's the difference?
In addition to distinguishing between artificial and natural light sources, we also differentiate between direct and indirect light sources. When light from a source hits an object without the intervention of other substances, it is called direct light. A straight line can be drawn between the light source and the illuminated object. Think, for example, of the sun and LED lighting. An indirect light source is a light source that emits light through a reflective surface. The moon emits light, but it is light from the sun. Sunlight shines on the moon, and the moon reflects that light back to Earth. Many lamps have a mirror behind the lamp. This mirror reflects light that is going in the wrong direction. So, a lamp also provides indirect light. This applies to our high-quality reflectors.