How do stars differ from planets?

Stars are massive incandescent gas (plasma) bodies that emit their own light, in contrast to planets, which shine with light reflected from a star. In the interior of most stars, thermonuclear reactions take place; such reactions do not occur in planets. The boundary mass is about 0.02 times the mass of the Sun, or about 20 times the mass of the planet Jupiter. With such a mass, an object can already be considered a star, in its interior, although at a low speed, hydrogen turns into helium.