Spiral galaxies are massive, rotating structures composed primarily of stars, gas, dust, and dark matter, characterized by a distinct flattened, rotating disk. Their most defining feature is the presence of prominent spiral arms, which are not fixed physical structures but rather density waves of enhanced star formation. These waves are believed to be caused by gravitational interactions within the galactic plane, leading to the continuous birth of new stars. The overall dynamics of a spiral galaxy involve differential rotation, where the angular velocity of the stars and gas increases with the radial distance from the core, creating a characteristic rotational bulge and a thinner outer disk.