Natural polymers are spontaneously synthesized by living organisms.
Artificial polymers are obtained by the chemical modification of natural polymers.
Synthetic polymers are obtained from simple organic molecules named monomers. Monomers are the building blocks used to generate macromolecules by means of polymerization reactions. In these reactions many monomer molecules bind together forming long chains of repeat units.
Polymerization reactions have been discovered by scientists. They can be made both in industry and in laboratory. They differ for the mechanism and the experimental conditions used, such as temperature, pressure, monomer concentration and so on.