Dyson Spheres
A Dyson Sphere is a hypothetical megastructure that partially or completely encompasses a star. It is designed to harness the star’s solar power and provide great amounts of energy to any space-faring civilization.
Dyson Spheres may completely surround a star (a Dyson Shell), may exist as a ring (a Dyson Ring), or may be composed of a network of individual satellites arranged like a bubble (a Dyson Bubble).
When including Dyson Spheres in your worldbuilding consider who built them, for what purpose is the star’s energy being harvested, and where the material to construct such a megastructure originated.

Dyson Spheres take their name from mathematician and physicist, Freeman Dyson, who was inspired by earlier science fiction worlds.
A complete shell around a star would disrupt the star’s heliosphere and potentially be subject to increased asteroid and comet strikes that would have otherwise been deflected by the star’s bow shock.
Bow Shock: A shockwave that occurs at the boundary between the magnetosphere of a celestial body and plasma such as the solar wind.