This document discusses classifications of polymers based on origin, monomer type, thermal response, formation method, structure, applications, carbon backbone, and morphology. Polymers can be classified as natural, semi-synthetic, or synthetic by origin; homopolymer or copolymer by monomer; thermoplastic or thermoset by thermal response; addition or condensation polymerization by formation method; linear, branched, or crosslinked by structure; used for plastics, fibers, elastomers, adhesives, or paints/coatings by application; organic or inorganic by carbon backbone; and crystalline, semi-crystalline, or amorphous by morphology.