Stochastic processes are mathematical objects used to describe systems that evolve over time in a random manner. They are essential in various fields such as finance, queueing theory, and statistical mechanics, where uncertainty and randomness play a crucial role in modeling real-world phenomena. These processes can be classified into different types, such as discrete-time and continuous-time processes, depending on how time is treated. Understanding stochastic processes allows researchers and practitioners to make predictions and analyze the behavior of complex systems under uncertainty.