Model

Something made to resemble something else, such as a miniature automobile or person (doll). A model has some features of the thing it represents but lacks others. As a result, it can be smaller, cheaper, more convenient, or otherwise more suitable for a certain purpose than the “real” object. In addition to physical models, there now are mathematical or computer models of complex phenomena, such as a business, a city, or a national economy. These computer models can be used to simulate actual or potential developments in the real world, and such simulations can guide policymakers in deciding on actions to take.