Simulation is the process of creating a model or representation of a real-world system or phenomenon to study its behavior under various conditions. This can involve computer programs, physical models, or even role-playing scenarios. Simulations are widely used in fields like engineering, medicine, and education to test theories, train individuals, or predict outcomes without the risks associated with real-life experimentation. In a simulation, users can manipulate variables and observe the effects, allowing for a deeper understanding of complex systems. For example, flight simulators help pilots practice flying without leaving the ground, while scientific simulations can model climate change to forecast future environmental conditions.