A Dyson sphere is a hypothetical structure that surrounds a star to capture its energy output. Proposed by physicist Freeman Dyson in 1960, this concept suggests that advanced civilizations could build such a structure to harness vast amounts of energy for their needs. There are different designs for a Dyson sphere, including a solid shell or a swarm of satellites orbiting the star. The idea is to maximize energy collection while minimizing waste. This concept is often discussed in the context of astrophysics and the search for extraterrestrial intelligence, as it could indicate the presence of advanced civilizations.