A data model organizes data elements and standardizes their relation to each other and the properties of real-world entities. Edgar F. Codd introduced the relational database model in 1970, which uses tables to make databases independent of other software applications. Database normalization is structuring a relational database to reduce data redundancy and improve data integrity.
Some data models are more generalized than the relational model, and one can classify them as post-relational models. A star schema is one such model and is the most common data model used in data warehouses. Star schemas are unnormalized and comprise at least one fact table that references many dimension tables.
Read the whitepaper “Model behavior: An introduction to data models” to learn more about two of the most common database models, a normalized relational database and unnormalized star schema, each of which has its advantages.