An ODS sits conceptually somewhere between a simple copy of an OLTP database for reporting purposes, and a full data warehouse (or atomic data store). Data warehouses and data marts consist of information that is summarised and reformatted to provide decision support at the enterprise and departmental levels. They do not address operational data access needs. Operational data stores are populated with information from operational systems and external data. The data typically remains close to its operational form rather than being transformed and enhanced, as it is for data warehouses and data marts. It is reorganised to provide detailed data efficiently, in the form most likely to be needed by operational staff for their reporting. Since there's less transformation involved, an ODS is typically updated frequently, possibly in real time alongside transactions performed in the OLTP systems