The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment designed to detect and measure gravitational waves, which are ripples in spacetime caused by massive cosmic events like merging black holes or neutron stars. LIGO consists of two facilities located in Hanford, Washington and Livingston, Louisiana, each featuring two long arms arranged in an L-shape. LIGO uses laser beams that travel down these arms and are reflected back by mirrors. When a gravitational wave passes through, it slightly alters the distance the laser beams travel, allowing scientists to observe these minute changes. This groundbreaking work has opened new avenues in astrophysics and our understanding of the universe.