Band of fabric that finishes the bottom of the sleeves. Like collars, cuffs come in an array of styles, but the three to know are below.

BARREL

A standard, functional cuff that is less formal than French cuffs. Most barrel cuffs have two buttons that provide a snug fit around the wrists, giving a neater look. Single button barrel cuffs are shorter and look more proportional to shorter arms, giving the illusion of longer arms.
Example shirt: Vaux
CONVERTIBLE

Can be worn as a Barrel or French cuff. To achieve this, a second button hole is placed between the buttons so it remains hidden when worn normally but can be opened up and worn with cufflinks. All the cuffs in the current collection are convertible cuffs, with the exception of Vaux.
Example shirt: Fletcher
FRENCH

A fashionable cuff that must be fastened with cufflinks in a business or formal setting.