Stellar Evolution. Lab 5. What is a Star?. The basic difference between a star and a planet is that a star emits light produced in its interior by nuclear 'burning‘ a planet only shines by reflected light. The Hertsprung-Russell Diagram.
The H-R diagram summarizes the types of stars in the universe:
Class Description Familiar Examples
White dwarfs stars are not classified because their stellar spectra are different from most other stars