Statistical mechanics is a sub-branch of physics which makes use of the principles of statistical methods and probability theory to determine the behavior of macroscopic systems. It attempts to understand the properties of these systems such as heat capacity, pressure, temperature, etc. by studying the microscopic entities which constitute them. Various calculations methods concerned with this subject are Monte Carlo method, perturbation theory and exact solution method. The applications of statistical mechanics include regression analysis of gravitational orbits, weather forecasting and neural networks. This book presents the complex subject of statistical mechanics in the most comprehensible and easy to understand language. It attempts to understand the multiple branches that fall under the discipline of statistical mechanics and how such concepts have practical applications. This book will serve as a valuable source of information for those interested in this field.