Macromolecular chemistry is the study of the physical, biological and chemical structure, properties, composition, and reaction mechanisms of macromolecules. A macromolecule is a molecule that consists of one or more types of repeated 'building blocks'. The building blocks are called monomeric units (monomers). Macromolecules (also known as polymer molecules) appear in daily life in the form of plastic, styrofoam, nylon, etc. These polymers (ie: substances consisting of polymer molecules), are of great technological importance and are used in the manufacturing of all sorts of goods, from automobile parts to household appliances. The artificial polymer molecules usually exist of long repetitions of identical monomers, either in chains or networks.