Super-Kamiokande is a large underground neutrino observatory located in Japan. It consists of a massive cylindrical tank filled with 50,000 tons of ultra-pure water, surrounded by thousands of light sensors. The facility is designed to detect neutrinos, which are elusive subatomic particles produced in nuclear reactions, such as those occurring in the sun. The observatory plays a crucial role in studying neutrino oscillation, a phenomenon where neutrinos change types as they travel. This research has significant implications for understanding the universe, including insights into particle physics and the fundamental forces that govern matter.