DATAWAREHOUSING(DWH)

What is dwh?what is dwh concept?
DWH is defined as the following-
a)maintaing database
b)analyzing database
c)controlling database
d)updating database
DATABASE is meant for bulk of data which can be analyzed,maintained,controlled and updated by using the concept of DWH.
DWH concept defined as maintaining the historical and the current data for a long period into data base,,,(10yrs,100yrs,...)....
eg: Banking sector,,,,suppose a person gone to a bank and asked to print his proceedings on his passbook of past 1yr then at the counter the bank employee cannot access all the 1yr information of that particular employee,BCOZ the bank maintains only 3 to 4 months of data of a particular employee in the server and remaining data will be in the hard copy like documents which can be in any godown,,,,it means that for maintaining only a one persons data of only 1yr is difficult in this sector,,just think how can we maintain   millions of ppls of data,,..so for this kind of process we use DATAWAREHOUSING concept,,..
TO maintain HISTORICAL AND CURRENT DATA we have many tools in market like
COGNOS,INFORMATICA,HYPERION,ORACLE BI,DBA,SIEBEL,,ETC....but only one tool that gives END TO END SOLUTION FOR DATAWAREHOUSING is SAP BI/BW.
This SAP BI/BW GIVES END TO END IMPLEMENTATION FOR THE DATAWAREHOUSING
CONCEPT,,,..............