This lecture introduces the importance of data modeling, describing methods and tools used in this context. It covers the role of modeling in geographic information systems, software engineering methodologies like Merise and RUP, and the Agile approach. The lecture explains the need to structure data, the entity-relationship model, and different types of associations. It also discusses the characteristics of classes and relationships, as well as specific modeling techniques like aggregation and generalization-specialization. Tools like CASE software and their role in creating and managing data models are also explored.