Weapons have elemental attributes which adds elemental effects to certain attacks when using specific weapons. There are five elemental attributes in the game: fire, water, lightning, light, and darkness.
Fire
Hitting enemies with a fire elemental attack will cause them to blow up when they hit the ground, causing additional damage to any enemy caught in the blast.
Water
Water elemental attacks will create water bubbles that will engulf the enemies heads, dealing continuous damage to them while the bubble is intact.
Lightning
Enemies hit by lightning elemental attacks will take extra damage when you attack them while they're airborne.
Light
Light elemental attacks will gradually increase your damage as you land consecutive attacks on groups of enemies. This is perfect when using Focus Spirit on a horde of enemies.
Dark
Darkness elemental attacks gradually increase your damage as you land consecutive attacks on a single enemy. This is generally great for fighting bosses.