The idea
A spreadsheet that answers back
In Excel a chart is a picture of one range of cells. Change the question and you rebuild the chart.
In Power BI you load the tables once, tell it how they join, and then every chart on the page filters every other chart. Click a region and the whole page becomes about that region.
That is the only real difference, and everything in this chapter serves it.
Check against your class slides. No Power BI material exists in the export, so this whole half is reconstructed from the outline's topic list and the textbook.