give me the difference please....
i will be blunt, since they have forced the combo system in every melee, it's difficult to get a huge difference.
the biggest difference is in the combo lenght, in the dragoon you have a very long cycle, when the monk is smaller and are more flexible (even if you want to reach the highest dps, you have a cycle quite fixed actually)

you will do your combo, placing skill out of GCD between weaponskill of your combo. moving for the right position (if you try to reach the best dps)

yeah we have another difference, is the speed between skill for the monk, is possible to reach below 1.9 gcd with the monk when a drg will be at best at 2.2.... outside this, we do have 2 DoT to place on the target, 2 main combo (one on the side and one on the back)
one skill that reduce the defense againsst our type of damage. the monk did get the meditation, where the dragoon did get the dragonblood, for the monk is a skill kinda hard to place, that will be charged when you can't fight. the dragoon can keep the dragonblood up the longuest possible passing him combo from 3 weapon skill at 4 weapon skill.

but in the absolute the two class play the same way, the difference lie in a few gimmick and a cycle that differe.... but if you look at the jobs in globality the difference are not that much.