Shortening

Shortening is a semisolid fat used in baking. It makes foods crumbly. Shortening doesn't smoke as easily as butter or oil, and it is 100% fat. Butter is 80% fat. It works by stopping long gluten polymers from forming in the food. It does not need to be refrigerated. It also is cheaper than butter. It can make foods last longer. 
Shortening is mostly made from hydrogenated oils, which have trans fats in them. Trans fats can cause heart attacks. People making shortening try to take out the trans fats.