What distinguishes a star from a planet?
Stars produce heat and light energy by fusion reaction inside their core. Planets only reflect light from stars.
Sun is a star.It is 1.3 million times by volume than Earth.
Most stars are in state of plasma 4th state of matter.
Planets orbit stars and only reflect the star light.
In night sky stars twinkle but planets does not.This is due to atmospheric refraction.