1. White Dwarfs: These are the dense remnants of stars that have exhausted their nuclear fuel and shed their outer layers. They are very hot but faint, hence appearing at the bottom left of the H-R diagram.
2. Red Giants: These are stars that have exhausted hydrogen fuel in their core and are now fusing helium in a shell surrounding the core. They are cooler but much larger than main sequence stars, hence appearing at the top right of the H-R diagram.
While these are the two most prominent types, other stars like supergiants and protostars also reside outside the main sequence on the H-R diagram.
