<P> Computer simulation reproduces the behavior of a system using a mathematical model . Computer simulations have become a useful tool for the mathematical modeling of many natural systems in physics ( computational physics ) , astrophysics , climatology , chemistry and biology , human systems in economics , psychology , social science , and engineering . Simulation of a system is represented as the running of the system 's model . It can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions . </P>
computer based models of real life situation are called
Computer simulations