Filament yarns consist of continuous fibers (filaments). Filaments can be produced by a natural spinning process (silk) or by wet, dry, or melt spinning processes (chemical fibers).
Source:
Eberle, Hannelore; Gonser, Elke; Hornberger, Marianne; et al. (2022), Fachwissen Bekleidung, 12. Auflage, Haan-Gruiten: Verlag Europa-Lehrmittel, S. 56