(This fiber refers to Textile fiber)
Natural fiber are naturally growing from Cotton plant.
Man made fiber are polyster,rayon,viscose staple fiber. Its is a process of wood pulp chemically treated and processed to make a fiber equal to natural fiber with same qualities.
viscose and cotton virtually have no difference.
But polyster have poor qualites compared to other in areas like thermal regain,moisture regain,softness,anti pilling,air premeabilty.