Data Warehouse – is a repository of information collected from multiple sources, stored under a unified schema, and that usually resides at a single site. It is a semantically consistent data store that serves as a physical implementation of a decision support data model and stores the
information on which an enterprise needs to make strategic decisions.
Data warehouses provide on‐line analytical processing (OLAP) tools for the interactive analysis of multidimensional data of varied granularities, which
facilitate effective data generalization and data mining. Many other data mining functions, such as association, classification, prediction, and clustering, can be integrated with OLAP operations to enhance interactive mining of knowledge at multiple levels of abstraction.