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Classification of Stars. At the top of this diagram are the Main Sequence stars, those using hydrogen as their nuclear fuel. The Sun is a G-type star, so you can compare that to the rare O-type stars to see the difference in size. And the difference in mass can be up to 100 times. Mona Evans"How Big Are the Biggest Stars"

Gamma Cephei A+B. (Image credit: Calar Alto) The visible star, called Gamma Cephei A, is an orange star nearly five times the radius of the Sun and coming to the end of its hydrogen fuel. It has a planet orbiting it, as well as a companion star. The other star is about half the Sun's mass, a faint red dwarf. Gamma Cephei B was known from its spectrum before it was finally imaged. ©Mona Evans, "Cepheus the King"