Data scrubbing which is also called data cleansing, is the process of amending or removing data in a database that is incorrect, incomplete, improperly formatted, or duplicated.
It is the process carried out before the data is moved into a data warehouse.

Data warehousing will support OLAP and OLTP.
→ ​ OLTP (Online Transaction Processing)​ is characterized by a large number of short online transactions (INSERT, UPDATE, DELETE). The main emphasis for OLTP systems is put on very fast query processing, maintaining data integrity in multi-access environments and an effectiveness measured by number of transactions per second. In OLTP database there is detailed and current data, and schema used to store transactional databases is the entity model (usually 3NF).
→ ​ OLAP (Online Analytical Processing)​ is characterized by relatively low volume of transactions. Queries are often very complex and involve aggregations. For OLAP systems a response time is an effectiveness measure. OLAP applications are widely used by Data Mining techniques. In OLAP database there is aggregated, historical data, stored in multi-dimensional schemas (usually star schema).

→ A staging area, or landing zone, is an intermediate storage area used for data processing during the extract, transform and load (ETL) process. The data staging area sits between the data source(s) and the data target(s), which are often data warehouses, data marts, or other data repositories.
→ Data staging areas are often transient in nature, with their contents being erased prior to running an ETL process or immediately following successful completion of an ETL process.
→ There are staging area architectures, however, which are designed to hold data for extended periods of time for archival or troubleshooting purposes.

→A data mart is a structure / access pattern specific to data warehouse environments, used to retrieve client-facing data.
→The data mart is a subset of the data warehouse and is usually oriented to a specific business line or team.
→Data Warehouse Bus Matrix is a diagram or tool developed by Kimball group to describe data warehouse design blueprint. It is component or consider as part of data warehouse architecture. It is visual picture of business process and conformed dimensions