Therefore: "to simulate is to model a (source) system through a different
system which maintains (for somebody) some of the behaviors of the
original system." The key term here is "behavior." Simulation does not simply
retain the—generally audiovisual—characteristics of the object but it
also includes a model of its behaviors. This model reacts to certain stimuli
(input data, pushing buttons, joystick movements), according to a set of
conditions.