A general power of appointment allows the holder to designate who receives property from a prior decedent through will or deed, including the ability to transfer the property to themselves, their estate, or creditors. In contrast, a special power of appointment only authorizes transferring the property to a restricted class of people, not including the holder themselves. Property subject to a general power of appointment is included in the holder's gross estate for estate tax purposes, while property subject to a special power of appointment is not.