For more than half a century, stochastic calculus and stochastic differential equations have played a major role in analyzing the dynamic phenomena in the biological and physical sciences, as well as engineering. The advancement of knowledge in stochastic differential equations is spreading rapidly across the graduate and postgraduate programs in universities around the globe. This will be the first available book for use by any undergraduate/graduate stochastic modeling/applied mathematics courses and for use by an interdisciplinary researcher with minimal academic background. "An Introduction to Differential Equations: Volume 2" is a stochastic version of Volume 1 ("An Introduction to Differential Equations: Deterministic Modeling, Methods and Analysis"). Both books have a similar design, but naturally, differ by calculi. Again, both volumes use an innovative style in the presentation of the topics, methods and concepts with adequate preparation in deterministic Calculus.