They are the same but people call different names. They call it FinFET because the shape of the device looks like a fin of a fish. I recalled that Prof. C.M Hu from Berkeley prefer tri-gate. (I don't remember clearly). The performance is better because it has a better subtreshold behavior. The gate has more control on the channel. If you are interested, you may go to Prof. C.M Hu to take a look. There should be some materials about trigate MOSFET.