Wool and silk are natural polymer fibres obtained from animals. Each is made up of fine threads, hundreds of times longer than they are thick.
Both wool and silk are made up of proteins called keratins.
Wool contains alpha-keratin which folds into coiled, helix type structures, whilst silk is made up of beta-keratin which folds backwards and forwards into flat sheet type structures.
Nylon is a synthetic fibre. It’s a polymer that feels smooth like silk but is wholly man-made in its creation.