A small handheld electric motor with two detachable beaters that spin in opposite directions, used to whip cream and egg whites, cream butter and sugar for cakes and cookies, beat batters smooth and mash potatoes, in whatever bowl the cook is already using. Most come with whisk and dough-hook attachments as well. It is the compact alternative to a stand mixer: cheaper, stored in a drawer, held over the bowl by hand.
Its motor is small, so it struggles with stiff bread doughs and very large batches, and the cook holds it throughout. For the whipping and beating that most home baking calls for it does the job in a few minutes. Start on low speed to keep flour and sugar in the bowl.