The sun is a star. It is the nearest star to Earth, which is why it seems much bigger than any other star, but really the sun is quite a small star. Some stars, that are much further away, are thousands of times bigger than the sun. The sun is a huge ball of fiery gasses. If the sun did not give us light and heat, there would be no life on earth, so the sun is very important to us. It takes Earth about 365 days, or one year, to travel once round the Sun.