How does archaeoastronomy assist archaeologists in comprehending the past of human societies? Archaeoastronomy is an interdisciplinary field that combines scientific principles and astronomical measurements to enhance our understanding of ancient cultures. Its interdisciplinary character appears by blending areas of the natural sciences, such as astronomy, physics, mathematics, and even geology or biology, with others of the social sciences and humanities, such as archaeology, history, prehistory, geography, or anthropology. Throughout this Element we are going to see what archaeoastronomy is about, how it works, and what topics it is applied to, for which we are going to introduce a series of concepts from astronomy, mathematics, and other disciplines.