A mathematical equation which relates some function with its derivatives is known as a differential equation. While applying a differential equation, the physical quantities are represented by functions and the rates of change are represented by derivatives. The relationship between the two is defined by a differential equation. There are several types of differential equations such as ordinary differential equations, partial differential equations and non-linear differential equations. Ordinary differential equations contain an unknown function of one real or complex variable x, its derivatives, and some given functions of x. A differential equation which contains unknown multivariable functions and their partial derivatives is known as a partial differential equation. A differential equation which is not a linear equation in the unknown function and its derivatives is known as a non-linear differential equation. This book provides comprehensive insights into the field of differential equations. Some of the diverse topics covered herein address the varied branches that fall under this category. Those with an interest in this field would find this book helpful.