Staging area is a place where you hold temporary tables on data warehouse server. Staging tables are connected to work area or fact tables. We basically need staging area to hold the data, and perform data cleansing and merging, before loading the data into warehouse.
Staging area is a temp schema used to
1. Do flat mapping i.e. dumping all the OLTP data in to it without applying any business rules. Pushing data into staging will take less time because there are no business rules or transformation applied on it.
2. Used for data cleansing and validation using First Logic