The sun is the largest star in our solar system, however there are many stars like it in the wider universe. The earth is just the right distance from the sun that our planet is not too hot or too cold. The light from the sun takes 8 minutes to reach earth and gives life to plants. Astronauts will never be able to land on the sun as it reaches 5500 degrees celsius - 100x hotter than humans can stand.
The sheer size of the sun means that its gravitational pull forces all the planets in our solar system to orbit around it. Born 5 billion years ago, the sun has been producing heat and light for a very long time.