Quasars, short for quasi-stellar radio sources, are extremely bright and distant objects powered by supermassive black holes at the centers of galaxies. They emit enormous amounts of energy across the electromagnetic spectrum, with some quasars being among the most luminous objects in the universe. Quasars are thought to represent a phase in the evolution of galaxies when their central black holes are actively accreting matter and producing intense radiation. Studying quasars provides insights into the early universe, galaxy formation, and the physics of black hole accretion.