The data may be gathered from a number of different sources but is collected together at one location for analysis. The data warehouse also provides an archive of the data.

Example : A supermarket may collect sales data from all its branches and store it together.

Data mining is the process of analysing all the data in the data warehouse to provide further information.

Example : The supermarket can analyse all the data from loyalty card schemes and establish long-term trends and buying patterns of customers. Customers can then be targeted with sales information and special offers.

Another example : Data warehousing makes sense in the insurance industry. Insurance companies have always captured large amounts of data. Changes in markets and customer needs have made this information a valuable strategic asset