Which command is used to create aggregated data sets in Power Query?

The command used to create aggregated data sets in Power Query is "Group By". This function allows users to summarize data by grouping it based on specified criteria, then applying aggregation functions such as sum, average, count, etc., to the resulting groups.

When working with large datasets, it is often necessary to condense information into a more manageable form. The "Group By" command facilitates this process by enabling users to define which columns to group data by and what aggregation metrics to compute. For example, if you have a sales dataset and you wish to know total sales per region, you can group the data by the region column and sum the sales amounts.

While "Merge" is used to combine datasets based on related columns and "Transform" refers to alteration operations applied to the data, and "Aggregate" does not exist as a distinct command in Power Query, it is the ability of "Group By" to organize and summarize that makes it the key function for creating aggregated data sets.