Modeling and prototyping are integral to the design and manufacturing process in many industries. Prototypes tend to be actual versions of the intended product, containing both the complete interior and exterior. They are used to learn something about a proposed system or product during the initial stages of development to mitigate the cost of discovering design errors later on. A model is a representation of the final product consisting of an arrangement of parts that serve to demonstrate the way the item will look like. Models can come in many shapes, sizes and styles and are commonly used for display.
A model doesn't have to work ... A prototype does.
If You’re asking for a difference between a scale model and prototyping, the simple answer scale models are the visual replica of a product that cannot be demonstrated in a small space, like a real estate, or an automobile. Prototype on the other hand, and life-size replica that can be used as a visual and functional representation of your product. Also, a prototype can be frequently worked upon to improve product design and functionality.
For smaller products, the term prototype and model can be used interchangeably. However, the key difference is between functionality. You can say that models are the prototypes used for visual representations only.