A system where the changes in the output and input are not proportional is called a nonlinear system. Most systems are inherently nonlinear in nature, and hence nonlinear problems are studied in various fields such as engineering, biology, physics, mathematics, etc. Unlike simple linear systems, nonlinear dynamical systems that describe changes in variables over time may appear chaotic, unpredictable or counterintuitive. Nonlinear systems are commonly approximated by linear equations since nonlinear dynamical equations are difficult to solve. This process of approximation is called linearization. This book provides significant information of this discipline to help develop a good understanding of nonlinear systems and related fields. From theories to research to practical applications, case studies related to all contemporary topics of relevance to this field have been included herein. This book is a vital tool for all researching or studying nonlinear systems as it gives incredible insights into emerging trends and concepts.