The difference between fiber and fiber: fiber is an American spelling and fiber is an English spelling. Fiber means fiber (of animals and plants), fibrous. Fiber means cellulose (in food), fiber products (such as fabrics or ropes), and fibers (of human or animal body tissues and natural substances). Examples of extended data fiber: gellulose forms the structural fiber of many plants (cellulose composition in tissue fiber fields of many plants); Example of fiber: Dried fruits are especially high in fiber (the cellulose content of dried fruits is especially high).