A conceptual data model captures the high-level data requirements as a collection of related concepts. It contains only the basic and critical business entities within a given realm and function, with a description of each entity and the relationships between entities.

For example, if we were to model the relationship between students and a school, as a relational conceptual data model using the IE notation, it might look like Figure 46.

Each School may contain one or many Students, and each Student must come from one School. In addition, each Student may submit one or many Applications, and each Application must be submitted by one Student.

The relationship lines capture business rules on a relational data model. For example, Bob the student can attend County High School or Queens College, but cannot attend both when applying to this particular university. In addition, an application must be submitted by a single student, not two and not zero.

Recall Figure 40, which is reproduced below as Figure 47. This dimensional conceptual data model using the Axis notation, illustrates concepts related to school: