This is an introduction to semantic data modelling which discusses the basis and consequences of semantic data modelling principles. Semantic data modelling is explained by referring to a large number of practical cases, demonstrating how practical use can be made of the advantages of semantic principles in both relational and network environments. Divided into four parts (overview, fundamentals, design, case studies), the text contains an overview of seven different semantic approaches, emphasizes practising data modelling concepts applied to simple cases, and features applications of modern data modelling techniques.