: The specific subset of data being calculated (e.g., a specific year or region selected in a report).
: Calculated on the fly based on report filters; more CPU-efficient and generally recommended for most analytical needs. Key Function Categories
DAX functions are categorized based on the problems they solve: Learn DAX basics in Power BI Desktop
: Computed at data refresh and stored in the model; best for filtering or grouping.
Understanding DAX requires more than just memorizing functions; it requires grasping how data is filtered and evaluated: