Polymer chemistry is diverse, defined as large molecules made up of chains or rings of linked repeating units (simple reactive building block compounds); formed from smaller molecules (monomers) combined to form polymers with a characteristic chain structure of multiple repeating units that can be related or different. They can be grouped into similar classifications, but differing somewhat in structure, performance, or what is considered the main component of the polymer; a corollary being "not all same named polymers are necessarily the same in performance or structural morphology". Typically the side groups on the backbone of the polymer influence the functional properties, even when present in small molar percentages. Understanding the contribution of the pendent side group and its resulting contribution to functionality will assist the formulating cosmetic chemist in proper selection for the desired results.