What is Datawarehousing Architecture..?

Datawarehousing inclueds two Phases 1) ETL 2) Reporting

The following Image shows both Phases ....
 

The following Diagram shows a Detailed ETL PHASE....

We have datasourses ODS1, ODS2, ODS3 and so on... These contain Operational Data or Real time data... These systems may locate in various placess across geographical regions..

We extract the data from these data sources and we keep the data in Staging area for a while and we apply  Data Transformations such as Data formatting, Data Cleansing, Data aggregations..Then we load the transformed data from Staging area into Datawarehouse,

A Datawarehouse is just a Database contains Fact tables and Dimension Tables to form Star Schema..