Simulation is the imitation of the operations of a real-world product, process or system over time. The key characteristics, functions or behaviors of the selected physical product, process or abstract system is represented in a 3D model in a designed virtual space. We can, for example, convert a model from CAD-drawings, from solidworks, pro/ENGINEER etc. Then the simulation represents the operations of the system over time.
Simulations are typically used for performance optimization, safety engineering, testing, training or education. The idea is to virtually demonstrate the real effects of courses of action and alternative conditions. It is also used when the real system is very expensive and comprehensive to test, is dangerous, or is still in its design or prototype phase.