An operational data store (ODS) is a type of database often 
used as an interim area for a data warehouse. Unlike a data 
warehouse, which contains static data, the contents of the 
ODS are updated through the course of business operations. 
An ODS is designed to quickly perform relatively simple 
queries on small amounts of data (such as finding the 
status of a customer order), rather than the complex 
queries on large amounts of data typical of the data 
warehouse. An ODS is similar to your short term memory in 
that it stores only very recent information; in comparison, 
the data warehouse is more like long term memory in that it 
stores relatively permanent information.

But in staging we are storing current as well as historic 
data. This data might be a raw and then need cleansing and 
transform  before load into datawarehouse.