The realization that deterministic dynamical systems can show dynamics that is as unpredictable as a coin-toss has had a profound effect on the manner in which we view complexity, uncertainty, and chance. In the past few decades, there have been significant advances in the study of nonlinear dynamical systems. In this talk, I will briefly discuss the history of the field, the different issues that are of interest, and applications of these ideas to areas such as synchronization and control, as well as to recent applications in biology.