Synopsis This book discusses the computer simulation which has become a useful part of modeling many natural systems in physics, chemistry and biology, human systems in economics and social science and in the process of engineering new technology, to gain insight into the operation of those systems. The present publication, an up-to-date guide addresses all aspects of a simulation study, including Modeling, simulation languages, validation, input probability distribution and analysis of simulation output data. This book should be a great help, as it attempts to explain the basic underlying principles of modeling techniques for ensembles of small and moderate sized molecules.