Data for a story can come from a file, a SAP Analytics Cloud model or dataset, or an outside data source.
Datasets
If you import data from a file or an outside data source, you create a dataset within the story. SAP Analytics Cloud has two types of datasets:
- Embedded: Embedded datasets are unique to that story and cannot be shared outside the story or refreshed.
- Public: Public datasets can be shared among different stories.
Neither dataset can be scheduled for a refresh, but you can manually re-import updated data. In addition, both datasets can be secured to allow users access to the dataset or not. Specific column-based or property security, however, is not supported for any datasets.
A limitation to a public dataset is that you cannot change its data source. For example, if your public dataset was originally created from a flat file but you now want to use an SAP BW query, you have no option to make that change. Embedded datasets, on the other hand, do allow you to change the data source via the 
Add New Data option.
You can also convert an embedded dataset into a model, but any transformations you made to the dataset are lost and must be recreated in the model. A public dataset cannot be converted to a model.
Data Preparation
You can prepare and transform the data to meet your story needs in the Data Preparation area. Here, you can change the data, including adding transformations using either a simple or more robust transformation editor.
Note
- If using data from SAP Datasphere, you directly access a SAP Datasphere model located in a specific space defined in SAP Datasphere.
- Data preparation is only possible with imported data. If you choose SAP Datasphere as your outside data source, you cannot manipulate the data because it is live, not imported.
