A filament is a continuous strand of fiber with much longer length than staple fiber. All man-made fibers are filament fibers, but only one natural fiber is filament fiber that is silk. Filaments are of two types; mono-filament and multi-filament.
Filament fibers refer to fibers of long continuous lengths, while staple fibers refer to those of shorter lengths, which are about a few inches long. Most natural fibers, such as cotton and wool, are staple fibers. Synthetic fibers, such as nylon and polyester, are considered filament fibers. The natural fiber silk is also a filament fiber, but when filament fibers are cut short, they are considered staple fibers.