When you take the Attack action and attack with a light melee weapon that you're holding in one hand, you can use a bonus action to attack with a different light melee weapon that you're holding in the other hand. Alternatively, if you're wielding a Duel-weapon, use it for both attacks. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

If either weapon has the thrown property, you can throw the weapon, instead of making a melee attack with it.

Duel-weapons. Any one-handed weapon without reach or versatile may be forged as a double ended weapon, being forged with a weapon on both ends of the grip. A double-ended weapon loses the following properties: concealable, grappling, light, parrying, and thrown. Additionally, it gains the two-handed property. While most double ended weapons are typically identical, such as the double-ended sword, you may mix two weapons if both follow the stated requirements.