What is the difference between stars and planets? The differences are numerous, and there are some stark differences between the two types of stellar bodies. Without stars, there would be no planets, and therefore there would be nothing to observe in the sky. Without planets there would be no life, and there would be no need to know the difference. Here are a few basic differences between what a planet is, and what a star is.
A star is much more massive than a planet, with even the smallest stars being several times more massive than Jupiter. If you put an average star next to Jupiter, it would also be more massive. The major thing that a star has is the ability to fuse hydrogen into helium, and this makes them really hot, and gives them the ability to shine brightly. Stars are able to do so because they are so massive that they can create the type of fusion necessary.
Since a star is much more massive than a planet, it has a greater gravitational pull. This is the reason that the Earth rotates around the Sun, and not the other way around. Stars are not immune to gravity, and the bigger the star, the more of a gravitational influence that it can have over the surrounding regions in space. Although we will never come close enough to see another star, it is speculated that perhaps interactions with nearby stars have caused increased periods of comet activity on Earth.
A planet is much smaller, and it will orbit a star. Unlike a star, which is mostly made up of hydrogen, and helium, a planet is usually more rocky. While some planets like Jupiter, or Saturn are gas planets, most planets will be made up of some sort of rocky surface. While stars are ultra-hot, planets are much cooler, and some can hang onto things like water. Water is essential to life, and no star would ever be conducive to life as we know it.
Planets are also pretty small relative to a star. Even an average star is going to be roughly 20 times the mass of Jupiter, which is by far the largest planet in the solar system. While stars are made up up of mostly hydrogen and helium, a planet can have elements like iron, nitrogen, and other elements. A planet also cannot produce its own light, and relies on a star to produce the light that illuminates any body.
So when you look up into the night sky, you will now know what makes up a planet, and what makes up a star. The stars are going to shine like little specks of light in the sky, becuse of the fusion going on inside the core. Planets will be what are orbiting those stars, and what will give rise to life. They are going to be smaller, and dependent on the star they orbit for light and warmth. A star is the center of an solar system, and without them, there would be no planets.