This article provides a detailed explanation on how to use Flux queries in InfluxDB Cloud or InfluxDB v2 for aggregating data across tags or fields, as well as ungrouping by using the group() function. It covers understanding the group key and its effect on table stream output, performing aggregations across fields or measurements, and ungrouping data with an empty group() Flux function. The article also includes a sample dataset to explore Flux and provides tips for interpreting Annotated CSV outputs.