How many types of data modeling are there, and what are the three major types?

Data modeling is typically divided into three layers: conceptual, logical, and physical. The conceptual model captures the high‑level business entities and relationships without technical detail, often expressed with ER diagrams or UML class diagrams. The logical model translates the conceptual design into a database‑agnostic structure, defining tables, columns, data types, and relationships, but still independent of a specific DBMS. The physical model maps the logical design onto a particular database system, specifying indexes, storage parameters, partitioning, and performance tuning. Understanding all three layers helps ensure that the database accurately reflects business requirements, remains portable across systems, and performs efficiently.