This is where the data is copied over from the staging area. There are several schools of thought that define the data warehouse:

• Kimball group data warehouse bus: Ralph Kimball was a pioneer in data warehousing. He and his colleagues wrote many books and articles on their method. It consists of conformed dimensions that can be used by many business processes. For example, if we have a dimension named DimCustomer, we should link it to all fact tables that store customers. We should not create another dimension that redefines our customers. The following link gives more information on the Kimball group method: https://www.kimballgroup.com.
• Inmon CIF: Bill Inmon and his colleagues defined the corporate information factory at the end of 1990s. This consisted of modeling the source systems commonly using the third normal form. All the data in the table was dated, which means that any changes in the data sources were inserted in the data warehouse tables. The following link gives more information on CIF: http://www.inmoncif.com.
• Data Vault: Created by Dan Linsted in the 21st century, this is the latest and more efficient modeling method in data warehousing. It consists of breaking down the source data into many different entities. This gives a lot of flexibility when the data is consumed. We have to reconstruct the data and use the necessary pieces for our analysis. Here is a link that gives more information on Data Vault: http://learndatavault.com.