For the formation of large macromolecules of different sizes and shapes the monomers are connected together and such a process is called polymerization.
The polymer is derived from the two Greek words: "Poly" means many and "mer" means parts or unit.
The repeating structural units are called monomers and they are bonded to form covalent bonds.
For example: The formation of Teflon from tetrafluoroethylene is an example of a polymerization reaction.