1. Different characteristics: the physical model intuitively shows the characteristics of the image in the form of physical objects or drawings. In the data warehouse project, physical model design and business model design support the implementation of the data warehouse as strongly as two wheels, and they are both in parallel and indispensable; Conceptual model is a conceptual data model, which is user-oriented and real-world-oriented, and has nothing to do with DBMS. Mainly used to describe the conceptual structure of a unit; The mathematical model is the abstraction and simulation of the evaluation problem, and each parameter is composed of factors related to the evaluation object.
2. Different classification: physical model. Middle school physical models can be generally divided into three categories: material model, state model and process model; In principle, there is no specific classification of conceptual models; Mathematical model, exact type, connotation and extension are very clear and can be expressed by precise mathematics, while fuzzy type, connotation and extension are not very clear and should be described by fuzzy mathematics.