See simulation.
Representation of a real-life situation in a computer program. For example, the program might simulate the flow of customers arriving at a bank. The user can alter variables, such as the number of cashiers on duty, and see the effect.
More complex simulations can model the behavior of chemical reactions or even nuclear explosions. The behavior of solids and liquids at high temperatures can be simulated using quantum simulation. Computers also control the actions of machines—for example, a flight simulator models the behavior of real aircraft and allows training to take place in safety. Computer simulations are very useful when it is too dangerous, time consuming, or simply impossible to carry out a real experiment or test.