If a weapon has the thrown property, you can throw the weapon to make a ranged Attack. If the weapon is a melee weapon, you use the same ability modifier for that Attack roll and damage roll that you would use for a melee Attack with the weapon. For example, if you throw a Handaxe, you use your Strength, but if you throw a Dagger, you can use either your Strength or your Dexterity, since the Dagger has the finesse property.