A French twist is a common "updo" hair styling technique. It is created by gathering hair in a low ponytail (not secured) and twisting the ponytail upwards until it turns in on itself against the head. It is then secured with pins, clips, sticks or a comb.
French twists are usually worn to proms and weddings when they are in a tight fashion; however, one could wear a messier, looser look to the office or out on the town. Hair clips are also commonly used with French twists. wiki