Quasars, short for "quasi-stellar radio sources," are extremely luminous and energetic galactic nuclei powered by accretion of material onto supermassive black holes at their centers. They are among the brightest objects in the universe and are characterized by their high redshifts and strong emission lines in their spectra. Quasars are believed to be the result of active galactic nuclei (AGN) and play a crucial role in our understanding of the evolution and dynamics of galaxies, as well as the nature of black holes and the early universe. Research on quasars involves studying their properties, evolution, and impact on their host galaxies and surrounding environments.