The Sun's current age is thought to be about 4.57 billion years, and is an averaged-sized star which contains approximately 99% of the total mass of our solar system.
About 74% of the Sun's mass is hydrogen, 25% is helium, and the rest is made up of trace quantities of heavier elements. Because of this, there are no craters on the sun, as it is entirely made up of gas.
The number of sunspots visible on the Sun is not constant, but varies over a 10-12 year cycle known as the Solar cycle. The solar cycle has a great influence on space weather, and seems also to have a strong influence on the Earth's climate.
The Sun orbits the center of the Milky Way galaxy at a distance of about 25,000 to 28,000 light-years from the galactic center, completing one revolution in about 225–250 million years.
Historically the Sun was thought to be a solar deity or other supernatural phenomenon, and worship of the Sun was central to civilizations such as the Inca of South America and the Aztecs of what is now Mexico.
Eratosthenes might have been the first person to have accurately calculated the distance from the Earth to the Sun, in the 3th century BCE, as 149 million kilometers, roughly the same as the modern accepted figure.
Information source: Wikipedia