The word model is used in various contexts meaning something (abstract or physical) that represents 'the real thing'. That entity may be anything from a single item or object (for example, a bolt) to a complete system of any size (for example, the Solar System). In general, a model is an object which we study, not for its intrinsic interest, but because it is a formalized or simplified representation of a class of phenomena which can be studied easily.
Modeling refers to the process of generating a model as an abstract representation of some real world entity.
Typically a model will contain only the significant features or aspects of the item in question, and two models of the same item may differ quite significantly. This may be due to differing requirements of the model's end user (one user may be interested in aspects of the item which are quite separate from those of another user) or, perhaps more simply, this may be due to the difference in perception of that item by the modeller and decisions made during the modelling process. This is why it is critically important for any end user to understand the original purpose or application for the model.
Models have applications throughout science with variations according to the subject matter under discussion. Abstract models such as statistical models and 'mathematical models'\ are used throughout the natural sciences including physics, chemistry, biology and economics. (See also: model theory, applied mathematics.)
A model is often a simplified version (cognitive model), but it can also mean an especially good or useful example of a process, or for studying a process such as a model organism in developmental biology.
A physical model of something large is usually smaller, and of something very small is larger.
A physical model of something that can move, like a vehicle or machine, may be completely static, or have parts that can be moved manually, or be powered.
A physical model may show inner parts that are normally not visible.
The purpose of a physical model on a smaller scale may be to have a better overview, for testing purposes, as hobby or toy.
The purpose of a physical model on a larger scale may be to see the structure of things that are normally too small to see properly or to see at all, for example a model of an insect or of a molecule.
A physical model of an animal shows how it is built without it walking or flying away, and without danger, and if the real animal is not available.
A soft model of an animal is popular among children and some adults as cuddly toy.
A model of a human may be a doll or a statue.
Modeling: the process of generating a model
Models in science
Physical models
See also
Modeling languages
Physical models