The theory of one-dimensional systems is an efficient tool in nonlinear dynamics. On the one hand, it describes one-dimensional systems fairly completely, and on the other hand exhibits all basic complicated nonlinear effects. This volume acquaints the reader with the fundamentals of the theory of one-dimensional dynamical systems. Very simple nonlinear maps with a single point of extremum, also called unimodal maps, are studied. Unimodal is found to impose hardly any restrictions on the dynamical behaviour. It also provides a view of the problems appearing in the theory of dynamical systems. and describes the methods used for their solution in the case of one-dimensional maps. The book should be of interest to researchers and postgraduate students whose work involves nonlinear dynamics.