Galaxy dynamics is the study of the motions and interactions of galaxies within the universe. This field of research focuses on understanding the gravitational forces that govern the behavior of galaxies, including their rotation, orbiting of satellite galaxies, mergers, and interactions with other galaxies. By studying galaxy dynamics, scientists can gain insight into the formation, evolution, and structure of galaxies, as well as the distribution of dark matter within them. This research area often involves observing and analyzing the movements of stars, gas, and other celestial objects within galaxies to better understand their dynamics and evolution over time.