Shortswords are martial, sharp weapons consisting on a blade light enough to wield in one hand that deal 1d6 piercing damage on a hit and have the Finesse and Light properties.

Properties

Finesse
When making an attack with a finesse weapon, you use your choice of your Strength or Dexterity modifier for the attack and damage rolls. You must use the same modifier for both rolls.

Light
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. You don’t add your ability modifier to the damage of the bonus attack, unless that modifier is negative. If either weapon also has the Thrown property, you can throw the weapon instead of making a melee attack with it.

Superior Strike

Skewer.
In a thrusting strike, you attempt to skewer an enemy with your weapon. Make an attack roll against a creature within your reach. On a hit, the target suffers the attack’s normal effects and is also grappled by you. This grapple ends early if you use the weapon to make another attack or you let go of the weapon. When the grapple ends, the creature takes piercing damage equalling a number of d8s equal to your proficiency bonus.