whats datawere house?

Concept of Data warehouse in the light of Databases:
before the data warehouse the database was based upon the operational transaction purpose using OLTP(online Transaction processing).But in the mid of 1980's the databases developer's realized that there is need of warehouse for the Manager's decision making.there fore the concept of data warehouse concept developed.And the Online Analytic Processing (OLAP) used to analyzing the data from the warehouse.which is the heart of Data warehouse.