Plain-English definitions of the core Power BI terms for PL-300 study. Simplified for learning; Microsoft documentation is authoritative.
| Term | Definition |
|---|---|
| Power BI Desktop | The free authoring app where you prepare, model and build reports. |
| Power Query | The data-preparation engine for cleaning, transforming and combining data. |
| M | The language behind Power Query transformations (mostly generated for you). |
| Applied Steps | The ordered list of transformations Power Query records and replays on refresh. |
| Append | Stacking the rows of two queries with the same columns. |
| Merge | Joining two queries on a matching key, like a SQL join. |
| Data model | The connected set of tables, relationships and measures behind a report. |
| Star schema | The recommended model shape: fact tables surrounded by dimension tables. |
| Fact table | A table of events or transactions (the numbers you measure). |
| Dimension table | A table of descriptive attributes (who, what, when, where). |
| Relationship | A link between two tables, defining how filters flow. |
| Cardinality | The relationship type: one-to-many, one-to-one or many-to-many. |
| DAX | Data Analysis Expressions - the formula language for measures and columns. |
| Measure | A DAX calculation evaluated at query time, used for aggregations. |
| Calculated column | A DAX value computed per row and stored at refresh. |
| Filter context | The set of filters acting on a measure when it is evaluated. |
| Time intelligence | DAX patterns for periods (year-to-date, prior year, and similar). |
| Visual | A chart, table, card or map placed on a report page. |
| Slicer | An on-canvas control that filters the report for the viewer. |
| Drill-through | Navigation to a detail page filtered to the selected item. |
| Bookmark | A saved state of a report page (filters, selection, visibility). |
| Workspace | A container in the Power BI service for collaborating on content. |
| Dataset (semantic model) | The published data model that reports connect to. |
| Scheduled refresh | Automatic updates of a dataset from its source on a timetable. |
| Gateway | A bridge that lets the Power BI service reach on-premises data. |
| Row-level security (RLS) | DAX roles that restrict which rows each user can see. |