Conical intersections refer to points in a molecular electronic state potential energy surface where two or more electronic states intersect. These intersections play a crucial role in various photochemical processes, such as internal conversion and non-radiative relaxation in molecules. Understanding conical intersections and their dynamics is important for elucidating the molecular mechanisms behind many chemical reactions and fundamental processes in photochemistry. Researchers study conical intersections using theoretical methods, spectroscopic techniques, and computational simulations to investigate their impact on the behavior of molecules in different environments.