Data sets are customized collections of data items that you use frequently. As you make updates to the data set, the dashboards, stories, or explorations that use that data set are also updated the next time you run them.
You can create data sets from packages or data modules, and use as sources to create dashboards, stories, explorations, and data modules.
You can't create a report directly from a data set. However, to use the data from the data set in a report, create a data module from the data set, and then use the data module as a source for your report.
The data set mechanism is based on the Cognos® Analytics report foundation. You add data to a data set in a similar manner as you add data to a list report. You can switch between Page design and Page preview modes. The Query view provides an alternative way to modify the data sets. In this view, you can copy and paste queries from existing reports, manage advanced filters and prompts, and rename queries.
Here is an example of a data set in the Page preview mode.