d924f03e_sselaer_Data_Warehouse_Project__data_warehousing_systems
[operational systems] Data within operational systems are generally updated regularly according to need. [data warehousing systems] 
Data within a data warehouse is generally non-volatile, meaning that new data may be added regularly, but once loaded, the data is rarely changed, thus preserving an ever-growing history of information. In short, data within a data warehouse is generally read-only.
Operational Systems vs. Data Warehousing - Rensselaer Data Warehouse Project
data warehousing systems