Supergiants are among the largest and most luminous stars in the universe. They have a mass that can be up to 100 times greater than that of our Sun, known as Sol. These stars are typically found in the later stages of their life cycle, having exhausted the hydrogen in their cores and expanded significantly. There are two main types of supergiants: red supergiants and blue supergiants. Red supergiants, like Betelgeuse, are cooler and larger, while blue supergiants, such as Rigel, are hotter and more massive. Both types are important for understanding stellar evolution and the life cycles of stars.