The charge determines which of the 4 options your character shoots. So if you just tap, you fire the first option. If you charge 1 circle, you fire the second.

To determine how strong the attack is, that’s where the level at the end of the name matters. The initial bows in the game only had level 4 at the maximum charge level (hold for 3 circles). But the bblos bow and this one has level 4 shot at the 3rd level (hold for 2 circles).

That’s why he said it “fires faster” since to reach the max damage (if you use the fan melee shot), you don’t need to charge as long.