The entity-relationship model is proposed as a data model that incorporates semantic information from the real world. A special diagrammatic technique is introduced to represent entities and relationships. An example of database design and description using this model is provided. The implications of the model on data integrity, information retrieval, and data manipulation are discussed. The entity-relationship model serves as a basis for unifying different data views, including the network model, the relational model, and the entity set model. Semantic ambiguities in these models are analyzed, and their data views are derived from the entity-relationship model. The structured design of relational and network databases using the entity-relationship approach is also discussed.The entity-relationship model is proposed as a data model that incorporates semantic information from the real world. A special diagrammatic technique is introduced to represent entities and relationships. An example of database design and description using this model is provided. The implications of the model on data integrity, information retrieval, and data manipulation are discussed. The entity-relationship model serves as a basis for unifying different data views, including the network model, the relational model, and the entity set model. Semantic ambiguities in these models are analyzed, and their data views are derived from the entity-relationship model. The structured design of relational and network databases using the entity-relationship approach is also discussed.