It's common for people to think in terms of "lasers" for most of the technology used in dermatology and and cosmetic or plastic surgery, but there are distinct differences.
Ultherapy uses ultrasound - which are sound waves. Most people are fairly familiar with ultrasound and anyone who has had a baby or knows someone who's had a baby has heard of ultrasound.
The difference in Ultherapy ultrasound is that the ultrasound waves are delivered in such a way that they meet at a focal point. It's this focal point that causes an intense generation of heat at a precise depth in the skin.
The heat causes a response that both immediately tightens and tightens over time as new collagen develops. It is this action that "lifts" the facial substructure...not as dramatically as surgery, but enough so that patients can appreciate the change.
Lasers for the most part are used to affect a specific "target" such as color - red or brown; or water. So with lasers you can get rid of brown patches or red vessels or dark hair or even vaporize tiny columns of tissue. Lasers can also have a mild tightening effect, but not as dramatically as Ultherapy.