Data Modeling is about representing the real world set of data structures or entities and their relationships in the form of Data Models, required for a database. Simply put, data model is a visual representation of the database.
Data Modeling consists of various types and phases like conceptual data modeling, logical data modeling, physical data modeling, enterprise data modeling, relational data modeling and dimensional data modeling.
Conceptual Data Modeling:
Conceptual Data Modeling visualizes the overall structure of the database and provides high-level information about the subject areas or data structures of an organization and it does not contain much detailed level of information about attributes.
Logical Data Modeling:
Logical Data Modeling is an extension to Conceptual Data Modeling and its includes almost all of the entities, attributes and their relationship. A logical Data Model will not contain any attribute specific information like type, length etc., instead it defines and conveys business information and rules.
Physical Data Modeling:
Physical Data Model includes data structures like tables, columns, properties and the relationship between them.
Enterprise Data Modeling:
Enterprise Data Modeling is known as global business model as it consolidates the information across the enterprise.
Relational Data Modeling:
Relational Data Model revolves around Entity-Relationship Modeling where entities(tables) are normalized to avoid possible redundancy and this type is the preferred technique in OLTP.