Some fundamental aspects of the kinetics of free-radical polymerization are reviewed. So-called classical results for rate and molecular-weight distribution are first of all presented. It is shown how this approach can be built upon when chain-length-dependent termination is allowed, which it always should be. Various termination models are considered, and it is illustrated that although the models are different, rather remarkably they give common, model-independent behaviour. Some leading experimental results regarding the chain-length dependence of termination are summarized, before the chain-length dependence of other reactivities, the variation of reactivities with conversion, and non-steady state experiments are briefly discussed. Finally, living free-radical polymerization as effected by a reversible termination agent is considered. An outline of the kinetics of these systems is given, with the oft-neglected importance of conventional termination being stressed.