The Solar System is the environment around our Sun. The Sun is a star. It is like most stars that we can see in the sky, but it is our star. Like other stars, the Sun is a large sphere of gas made mostly of hydrogen. Nuclear fusing taking place in it core causes the Sun to radiate light and energy. Orbiting around our Sun are a variety of bodies that make up our Solar System. These bodies include planets, asteroids, comets and other objects, each of which are in orbit around the Sun. Here is a representation of the solar system that shows the major bodies in orbit, the planets. The image shows the relative sizes of the planets, although their distance from the Sun is greatly reduced. You can see the Sun at the left is too large to be fully shown.
For perspective, here is an image that shows the relative sizes of the terrestrial planets including Earth. You can see that Earth is the largest of these planets.
Adding the gas giant planets, you can see how much larger these planets are, compared to the Earth.
When the Sun is added, you can see how large is our Sun.