In computing, a data warehouse (DW or DWH), sometimes known as an enterprise data warehouse (EDW), is a system that is used for reporting and data analysis. It is regarded to be a critical component of business intelligence because of its widespread usage. The term "data warehouse" refers to a central repository that stores integrated data from one or more diverse sources. They consolidate current and historical data into a single repository, which is then utilised to generate analytical reports for usage by employees across the organisation.
All of the information in the warehouse is transferred from the operating systems (such as marketing or sales). In certain cases, data may flow via an operational data store and may need data cleansing for extra procedures in order to verify data quality before it is utilised in a data warehouse for reporting.
Creating a data warehouse system is accomplished via the use of two primary approaches: extract, transform, and load (ETL) and extract, load, transform (ELT).