- Amorphous - Without a defined shape; fibers composed of a loose arrangement of polymers that are soft, elastic, and absorbing (for example cotton)
- Crystalline - Regularly shaped; fibers composed of polymers packed side by side, which make it stiff and strong (for example flax)
- Fiber - The smallest indivisible unit of textile, it must be at least 100 times longer than wide
- Mineral fiber - A collection of mineral crystals formed into a recognizable pattern
- Monomer - A small molecule that may bond to other monomers to become a polymer.
- Polymer - Substances composed of long chains of repeating monomers.
- Natural fiber - A fiber produced naturally and harvested from animal, plant, or mineral sources.
- Synthetic fiber - A fiber made from man-made substances such as plastic or petroleum
- Textile - A flexible, flat material made by interlacing yarns or threads.
- Yarn - Fibers which have been spun together.