Users can retrieve persisted data using the queries. A query allows the user to specify what fields to retrieve based on certain conditions. Moreover, a query allows the user to retrieve the data in a certain order and a certain grouping. Queries that are repetitive and essential to the functionality of an application can be saved, so that they can be re-executed without having to specify the fields to return, the conditions, the sort order and the groupings every time.
For specific details on retrieving data, see page entitled the Query API.