Lyman continuum refers to the range of ultraviolet radiation with wavelengths shorter than 912 angstroms. This range of radiation is important in astronomy and astrophysics as it ionizes hydrogen atoms by removing their electrons, leading to the formation of HII regions and the emission of Lyman-alpha radiation. The study of Lyman continuum radiation is crucial for understanding the ionization and heating processes in the universe, as well as the formation and evolution of galaxies and stars.