O-type Main-Sequence Stars are among the hottest and most massive stars in the universe. They have surface temperatures exceeding 30,000 Kelvin and are typically blue in color. These stars are very luminous, often shining thousands of times brighter than our Sun. Due to their high mass, they burn through their nuclear fuel rapidly, leading to shorter lifespans of only a few million years. These stars are crucial for understanding stellar evolution and the dynamics of galaxies. They produce heavy elements through nuclear fusion and contribute to the chemical enrichment of the universe when they explode as supernovae. Their intense radiation also influences the formation of nearby stars and planetary systems.