There are 3 main kinds of apparel textile fibers: natural, man-made, and synthetic.

Natural fibers grow in nature; wool, cotton, linen, and silk are prime examples

Man-made fibers come from living things but are not grown as fibers. For example, rayon, Tencel, acetate, tri-acetate all come from cellulose which is another word for wood pulp. The difference between these fibers is a combination of the type of wood pulp and the way it is dissolved and extruded into fiber form. This gives these fibers different characteristics such as touch and wet strength.

Synthetic fibers come from petroleum products and are created in the laboratory producing their own set of characteristics. This is the world of Polyester and Nylon.

All three of these fiber types are available in blended format to some degree.