With a focus on applications, this unique introductory book goes beyond the standard facts typically presented in probability texts. It includes a variety of stochastic models of real phenomena and methods of modeling, such as simulation, Markov chains, counting and compound processes, simple trees, queuing theory, reliability models, diffusion, and models of the financial market. It contains numerous examples from various fields, including economics, finance, insurance, computer science, and physics. The text also provides examples and exercises on numerical calculations using Excel.