Characteristic similarities and differences in polycondensations of ‘a − b’ and ‘a2 + b2’ monomers are described including cyclic ‘a − b’ and cyclic ‘a2’ monomers. Polycondensations of ‘ab3’ monomers that yield (hyper)branched polymers are compared with polycondensations of ‘a2 + b3’ monomers that yield (hyper)branched, multicylic, or crosslinked polymers. In all cases the influence of cyclization reactions on structure and molecular weight of the reaction products is considered. Furthermore, the definitions of polycondensation and condensative chain polymerization are discussed along with a differentiation between kinetically controlled and thermodynamically controlled polycondensations.magnified image