There is little difference. Some planets, like Venus and Jupiter are brighter than the stars. Perhaps the most obvious difference would be revealed if you look at the night sky every night for a few months. The planets will move against the backdrop of the constellations. The stars will not move. The movement of the stars in relationship to each other is very, very slight even across thousands of years! The constellations, like Orion, the Big Dipper, etc. are fixed in relationship to each other. The planets move through the constellations. The word "planet" comes from a Latin word meaning "wandering star".