All data entry in DHIS2 is organized in data sets. A data set is a collection of data elements grouped together for data entry and data export between instances of DHIS2. To use a data set to collect data for a specific organization unit, you must assign the organization unit to the data set. Once you have assigned the data set to an organization unit, that data set is available in the Data entry app. Only the organization units that you have assigned the data set to can use the data set for data entry.