What is a star?

Stars are huge balls of burning gas that are scattered throughout the universe. They burn for millions of years, giving off both light and heat. Stars produce energy by a process called Nuclear fusion. The coldest stars are coloured red and are dim, while the hottest stars give off blue-white light. The temperatures on the surface range from 3500 degrees celcius for the coldest star to over 40000 degrees celcius for the hottest star. A new star is born when gas and dust are drawn together by gravity, forming a huge clump. It heats up until Nuclear Fusion begins, and the new star appears.