Trojan objects are most easily conceived as orbiting at a Lagrangian point 60 degrees ahead of or behind a planet or moon in a type of 1:1 orbital resonance; in reality, they oscillate (librate) around such a point.
Trojan objects are most easily conceived as orbiting at a Lagrangian point, a dynamically stable location 60 degrees ahead of or behind a planet or moon in its orbit, where gravitational and centrifugal forces are balanced, in a type of 1:1 orbital resonance. In reality, they oscillate (librate) around such a point.