With this option, you can choose which Workspace you would like to explore.
You will find a list of Dimensions and Measures based on your workspace field types. The more dimensions you add, the more detail you get.
For example, if you have an e-commerce store and would like to explore your numbers of orders. If you have a status field for first-time customers, you can add it as a dimension and sum of Orders to as a measure. This would be a way to check the sums for the first time and returning costumers separately.
This method can be used to add detail about any field you have added to your workspaces as criteria to group data.
The Measures list contains calculations of your numerical values, such as Sum, Average, Min, and Max.
You can select which Dimensions and Measures you would like to explore and then press Run to explore the data in a table or in some of the graph options that could be formed with such combination.