Astronomy is the branch of physics that studies celestial bodies and the universe as a whole. It is the science involving the observation and theories about the solar system, the stars, the galaxies, and the general structure of space. Astronomy also includes cosmology, which is the study of the structure, origin, and evolution of the universe.
Physics is the science of matter and energy and their interactions. It is the branch of science that describes matter, energy, space, and time at its most fundamental level. The goal of physics is to find the most basic laws that govern the universe.