An ODS is a database designed to integrate data from multiple sources for additional operations on the data, for reporting, controls and operational decision support.
An ODS should not be confused with an enterprise data hub (EDH).
An operational data store will take transactional data from one or more production systems and loosely integrate it, in some respects it is still subject oriented, integrated and time variant, but without the volatility constraints.
Because the data originates from multiple sources, the integration often involves cleaning, resolving redundancy and checking against business rules for integrity.
An ODS is usually designed to contain low-level or atomic (indivisible) data (such as transactions and prices) with limited history that is captured "real time" or "near real time" as opposed to the much greater volumes of data stored in the data warehouse generally on a less-frequent basis.