Map of the Solar system containing all the planets and their named moons. The map also contains some important asteroids, dwarf planets, and trojans. Every celestial body is in log-scale. The orbits are not to scale in order to fit everything nicely in the image.
"What are Trojans?"
They are asteroids in the same orbits as the planets, where they are either 60 degrees ahead or behind the planet.
Trojan asteroids are asteroids that orbit Lagrange points 4 and 5. That is, there are two stable points in the Jupiter-Sun system (and any other orbit for that matter) where gravity cancels out and asteroids can hang out. Lagrange points 1, 2 and 3 are similar but unstable so they can't be orbited.