What is white shortening?

Answer 1

White shortening is just another term for plain shortening. It's used to distinguish from butter-flavored shortening.

If you're not from the US or Canada and don't know what shortening is at all, it's made from partially-hydrogenated vegetable oil and is used as a substitute for lard and butter in recipes and as an oil for deep-frying. It has no flavor of its own and is there strictly to make the dough or short. Substituting butter or lard can be difficult because shortening has some air whipped into it, but for recipes like drop cookies where you can afford to play fast and loose with the measurements a one-to-one substitution of butter often works (and works better than shortening, sometimes).