Galaxy formation begins with the gravitational collapse of gas and dust in the universe. Over time, these materials clump together, forming dense regions that attract more matter. As the density increases, the temperature rises, leading to the formation of stars within these regions. Once stars form, they can influence their surroundings through radiation and stellar winds, helping to shape the galaxy. The interactions between stars, gas, and dark matter contribute to the overall structure of the galaxy, which can take various shapes, such as spiral or elliptical, depending on the conditions present during formation.