All weapons within a class (e.g. longswords, daggers) share the same moveset, and the basic attacks (light and heavy) are pretty simple. In a few cases, for example with the Fighter and their straight swords, a core skill for that vocation can be learned to develop your basic attacks a little bit more. The real depth, though, comes from the various weapon skills that you can equip. Using the Fighter as an example again, you can learn numerous sword and shield skills and equip three of each, granting you a variety of combat and other abilities.
Unfortunately, as I said before, even with these advanced skills, the weapons within a class all perform the same in terms of moveset. One of my few gripes with the game.