Many combat abilities generate weapon resources, which you can use for additional effects and damage. For example, certain Actives require a specific number of weapon resources before they can be activated. The way you acquire weapon resources during combat and the way they are displayed depend on the type of weaponry you use.
Weapon Types
Dual Weapons
Since you are able to equip up to two weapons at a time, it is possible to have two weapon resources on the screen at a time. This means if you are wielding a Ranged weapon and a Magic weapon, you will see weapon resources build on the target and under your health bar.
Many abilities that build a resource for one of your weapons automatically build a resource for your second weapon. This is how most resource building abilities work, unless the ability specifies otherwise.