What light sources do you know?

Sources of thermal radiation are the Sun, incandescent lamps;
cathodoluminescent – advertising lamps, daylight;
chemiluminescent – Christmas tree decorations covered with special paint, clock dials.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.