A Dyson sphere is a theoretical structure of massive size but it doesn’t exist in reality because it is a hypothetical entity. The Dyson sphere is so huge that it is envisioned to completely envelop a star and thus allow it keep the energy radiated by the reactions that take place in the star’s core.
Celebrated physicist Freeman Dyson first theorized the dyson sphere in his 1959 article published in Science, entitled “Search for Artificial Stellar Sources of Infra-Red Radiation.” But Dyson also got the idea originally from a science fiction novel written by Olaf Stapledon. The novel, Star Maker, was published in 1945.
The original concept for the Dyson sphere was not actually a sphere. The idea was to use ~10^5 objects, that together will absorb a majority of the star’s solar energy. This original idea, called the Dyson swarm, allows the staggered construction of the whole system. The individual components will orbit the star independent of each other. Seen from the outside, the swarm will appear black and will only emit infrared radiation. In fact, some infrared telescopes are currently searching for Dyson spheres or swarms for many years. But up to now, nothing has been discovered. One speculation is that if the objects are using reflectors on the interior, any kind of radiant energy will be oriented in one direction, and this will make it hard to detect from great distances.
Based on the studies of scientists, the solar system has enough rigid matter to enable the construction of a Dyson swarm but a Dyson sphere is a long shot because of the higher requirements needed.