Cosmology is the scientific study of the universe's origin, evolution, and eventual fate. It explores big questions like how the universe began, what it's made of, and how it changes over time. Cosmologists use observations from telescopes and other instruments to gather data about distant galaxies, stars, and cosmic events, helping us understand the vastness of space. One of the key concepts in cosmology is the Big Bang, which is the leading theory explaining how the universe started from a hot, dense state and expanded over billions of years. This field also examines mysterious phenomena like dark matter and dark energy, which make up most of the universe but remain largely unknown.