Photon interaction refers to the ways in which photons, the basic units of light, engage with matter. When photons encounter atoms or molecules, they can be absorbed, reflected, or transmitted. This interaction is fundamental to various processes, such as photosynthesis in plants and the functioning of solar panels. Different materials respond to photon interaction in unique ways. For instance, in transparent materials like glass, photons pass through with minimal absorption, while in opaque materials, they are mostly absorbed or reflected. Understanding these interactions is crucial in fields like optics and photovoltaics.