The Universe is massive and incredibly old, older than everything contained within.
The solar system comprises of a star and all the objects that travel around it- moons, planets, comets, asteroids, meteoroids etc. Solar systems can have more than one star called as binary star systems; with more than two stars they are known as multi-star systems.
Our Solar system consists of the stars, the Sun, and all the planets that orbit around it including the Earth. It also includes numerous moons, asteroids, comets, rocks and dust. The Sun is simply one star amongst the hundreds of billions of the stars present in the Milky Way Galaxy.