It is is a fine white powdery flour, with a bit of a sheen to it,.
It is made from corn (aka maize), dried and ground that has first had the hull and seed germ are removed through pounding, then the seed germ pounded off, leaving just the pure starch part of the seed.
The seed is then ground.
It is often made at home.
As in the Western world, where white flour is preferred to whole wheat flour, Ufa Woyera is preferred to its wholegrain version, Ufa Ngaiwa, becasue it cooks up both whiter and smoother.