A database model that focuses on decision support outcomes rather than the normal relationships between data sets as in an entity relationship (ER) model. ER models are "normalized" models that are designed to reduce redundancy and provide fast online transaction processing. An ER model of a company's data may result in hundreds of data tables, and complex queries become extremely cumbersome to formulate.
In contrast, dimensional models are many-to-many relationships that deal with the way business people think about their operation. The "fact table" is the highlight of a dimensional model and is visualized at the center of a star schema surrounded by dimension tables. See entity relationship model