What is the difference between comet and star?

Answer 1

Comets are very small and cold. They do not shine with their own light, but instead reflect the light of our sun.

Stars are huge and hot. Our sun is about a billion times bigger than any comet in our solar system. Although many stars may be smaller than our sun, many are far, far larger and brighter. Our sun only looks big and bright because it is so close. It is 8 light minutes away, whereas the next nearest star is 4.3 light years away, and the rest that we can see range from six light years to a few thousand light years.