Cosmology is the scientific study of the universe's origin, evolution, and eventual fate. It explores the large-scale structures of the universe, including galaxies, stars, and cosmic background radiation. Cosmologists use observations and theoretical models to understand how the universe began with the Big Bang and how it has changed over billions of years. This field combines aspects of astronomy, physics, and mathematics to answer fundamental questions about the nature of space and time. Cosmology also investigates concepts like dark matter and dark energy, which are believed to make up most of the universe's mass-energy content, influencing its expansion and structure.