they are more attracted to their planet than to their sun.
their diameter is at least an order of magnitude less than their planets
their orbits around their sun is a mix of convex and concave caused by their orbits around their planet
they can experience tidal forces from planets and other moons, but do not induce significant tidal forces in their planet
*all of these facts are true for every single known moon except for one- Luna, our "moon" (more like sister planet, agreed by the European Space Agency which refers to Earth and Luna as a double-planet system)
(For those who think it's a moon because the Earth-Luna barycenter is within earth, I'd point out that the Jupiter-Luna barycenter is always within Jupiter, and if Jupiter and Mars swapped spots the same would be true for Mercury and Jupiter (Mercury would essentially continue it's normal orbit around the Sun))