When do you use ISFILTERED Function (DAX)?

In our daily office work, we use Excel to ease our work, and people who know the use of PivotTable can generate reports with a fingertip. But in PivotTable there have few limitations that you can't use Functions. So here comes PowerPivot for Excel to give advanced flexibility over PivotTable. In PowerPivot for Excel and Power BI, you can write measure to give flexibility in report generating. So how this title is related to the [...]