In the world all the system undergoing change either decay directly or growth/decay exponentially can be described with the help of differential equations have a remarkable ability to predict the world around us. They are used in a wide variety of discipline such as physics, chemistry, biology and engineering. A differential equation is one which is written in the form of dy/dx=................ Some of these can be solved to get y =............. Simply by integrating or other require much more regrous mathematical method and the result comes by solving the diff. equations which will explain the very interesting phenomenon relating to physics and other disciplines also.