Our Sun is a star. It seems much bigger than other stars in the sky because it is much closer to Earth. Stars form immense groups called galaxies. A galaxy can contain many millions of stars, held together by the force of gravity.
Our Sun is in a spiral galaxy called the Milky Way. The Sun is about half-way from the centre of the galaxy, on one of the arms.
The distances between objects in space are huge:
This means that the numbers used to describe distances in space become very difficult to understand and to write down. For example, the distance between the Earth and the Sun is about 150,000,000,000 m but the distance to the next nearest star (Proxima Centauri) is 39,900,000,000,000,000 m.
To get around this problem, scientists use the light year as the unit of astronomical distance. It is the distance travelled by light in one year. So, for example:
It takes light from our Sun about 8 minutes to reach the Earth.