In many organizations, we want a central “store” of all of our entities, concepts, metadata, and historical information . For doing data validation, complex mining, analysis, prediction, … and this is the data warehouse.
To be more precise , data warehouse is simply a single, complete, and consistent store of data obtained from a variety of sources and made available to end users in a way they can understand and use it in a business context.”
One of the “modern” uses of the data warehouse is not only to support analytics but to serve as a reference to all of the entities in the organization.
In breif , Data warehouse is a collection of data that is used primarily in organizational decision making .And In order for data to be effective, Data Warehouse must be: Consistent ,Well integrated ,Well defined and Time stamped.