Dark energy is a mysterious force that makes up about 68% of the universe. It is believed to be responsible for the accelerated expansion of the universe, which means that galaxies are moving away from each other faster over time. This phenomenon was discovered in the late 1990s when astronomers observed distant supernovae. Despite its significant role, little is known about dark energy. It does not emit light or energy, making it difficult to detect directly. Scientists are still trying to understand its nature and how it influences the overall structure and fate of the universe.