A galaxy is a massive system of stars, stellar remnants, interstellar gas, dust, and total dark matter, bound together by gravity. These immense cosmic structures range widely in size and shape, with common classifications including spiral, elliptical, and irregular morphologies. The stars within a galaxy are not randomly distributed; they often follow discernible patterns based on the system's dynamics and formation history. Galaxies are the largest observable constituents of the universe, frequently existing in groups or clusters, which represent even larger concentrations of matter. The ongoing gravitational interactions between galaxies are critical forces shaping the evolution and distribution of matter throughout cosmic time.