Actinology is a term that refers to the study of the effects of sun rays on living organisms. However, there are many other words that can be used interchangeably with actinology. For example, photobiology focuses on the interaction between light and biological systems. Heliotherapy is the use of sunlight for therapeutic purposes. Solar radiation is a broader term that encompasses all forms of radiation emitted by the sun. Radiant exposure refers to the amount of light energy that falls on a surface. Ultraviolet radiation is a specific type of radiation that causes sunburn and skin damage. Regardless of the term used, the study of sun rays and their effects is an important field of research in biology and medicine.