Galactic dynamics is fundamental to understanding the formation of galaxies, their internal evolution and their current structure. While galactic dynamics has traditionally focused on the evolution of the stellar components of galaxies, studies over the past two decades have shown that all aspects of galaxy evolution are strongly influenced by the interplay between the dynamics of stars, gas, and dark matter. IAU Symposium 353, is the first major symposium in more than a decade focused on the dynamics of galaxies and stellar systems, covering the recent explosion in the availability of kinematical data both for individual stars in the Milky Way and wide field line-of-sight kinematics for large samples of external galaxies. These proceedings describe recent developments that aim to transform our understanding of the dynamics, structure, formation and evolution of our own host galaxy, the Milky Way, as well as galaxies in the universe at large.
Galactic dynamics studies the motions of stars and gas in galaxies to understand their structure and evolution. New observations, from satellites such as Gaia, allow us to validate our theoretical models. These and other large data sets provide insights into how our Milky Way relates to the universe of galaxies.