This book provides an introduction to stochastic analysis in an easy-to-understand format implied for a wide audience, from students of mathematics to practitioners in biology, chemistry, physics, and finances. It includes information on Brownian motion, motivation of stochastic models with Brownian motion, It? and Stratonovich stochastic integrals, It?'s formula, stochastic differential equations (SDEs), solutions of SDEs as Markov processes, application...