Dark Energy is a mysterious force that makes up about 68% of the universe, driving its accelerated expansion. Unlike ordinary matter and energy, which exert gravitational attraction, Dark Energy appears to have a repulsive effect, pushing galaxies apart. This phenomenon was first observed in the late 1990s through studies of distant supernovae. Scientists are still trying to understand the nature of Dark Energy, as it challenges our current understanding of physics. Various theories exist, including the cosmological constant and dynamic fields, but no definitive explanation has been established yet. Research continues to uncover its secrets and implications for the universe's fate.