The Sun is a star. It is a gigantic ball of very hot, glowing gas. It gives out huge amounts of light and heat.
The Sun is much bigger than the Earth — more than a million Earths could fit inside it. It looks small in our sky because it is about 150 million kilometers away.
There are many other stars, but they are so far away that they look like tiny dots at night. The Sun is the nearest star to Earth, so it looks big and bright.
Without the Sun, Earth would be dark and frozen. Plants use sunlight to make their food, and animals eat plants, so almost all life depends on the Sun.
Sunlight can also harm us. Never look straight at the Sun. Protect your skin with a hat, sunscreen, clothing and shade.