1.Planets are stars are both heavenly bodies mostly observable to the naked eye.
2.A star has its own light while a planet has no light of its own. It shines by reflecting the light of the sun.
3.Stars twinkle at night while planets don't.
4.Stars are large collections of gas that have a nuclear reactor at their core, whereas planets can be almost as large but lack the nuclear reactor.
5.A star has very high temperature while a Planet has very low temperature
6.Stars are the first to form when a new solar system is being created and planets are created later within the orbit of the star.
7.Throughout history mankind has been observing both stars and planets.