Light (weapon property)
For an explanation of all weapon properties, see Weapons.
Light is a weapon attribute that allows characters to dual wield weapons (that is, wield two Light weapons, one in the Main Hand and one in the Off-hand).
When Dual Wielding, you use your Action to attack with the Main Hand and your Bonus Action to attack with the Off-hand. You can use the Dual Wield toggle on the hotbar to control whether these attacks are made together or separately.
By default, you cannot add your Ability Score Modifier to the damage of the Off-hand Attack.