The microderm is a dry exfoliation using diamond tip abrasive wands and suction.  Microderm is a slightly more aggressive treatment then the HydraFacial.    HydraFacials are using moisture solutions whilst exfoliating and infusing vitamins and hydrators into the skin.  All skin types can have both treatments, the Microderm also has an option for a more intense AHA peel upgrade, enhancing the treatment results.