Polymers are large macromolecules characterized by a structure composed of repeating subunits, known as monomers, that are linked together through chemical bonds. The process by which these units join is called polymerization, which can occur through various mechanisms depending on the chemical bonds involved. These substances are fundamentally important across multiple scientific disciplines: in biology, polymers form the foundational structures of genetic material and complex structural proteins, enabling life processes. In physical science and technology, polymers are utilized to create a vast array of man-made materials, including plastics, fibers, and resins. The properties of polymers—such as elasticity, rigidity, and chemical resistance—can be highly modified by altering the type of monomer used or the manner in which the chains are synthesized, allowing for specialized applications in engineering and manufacturing.