Astronomical models are theoretical frameworks used to explain the structure and behavior of celestial bodies and the universe. These models help scientists understand phenomena such as the formation of stars, the movement of planets, and the expansion of the universe. They can be based on observations, mathematical equations, and simulations. There are various types of astronomical models, including the geocentric model, which places the Earth at the center of the universe, and the heliocentric model, which positions the Sun at the center. Modern models often incorporate concepts from physics and cosmology to provide a more accurate representation of the cosmos.