Import vs. DirectQuery vs. Live connection. Which do you choose and why in Power BI? Adam looks at the three options when creating reports in Power BI Desktop including composite models.

Power BI Data Sources:
https://docs.microsoft.com/power-bi/connect-data/power-bi-data-sources

Star Schema:
https://docs.microsoft.com/power-bi/guidance/star-schema

DirectQuery model guidance:
https://docs.microsoft.com/power-bi/guidance/directquery-model-guidance

Composite Model guidance:
https://docs.microsoft.com/power-bi/guidance/composite-model-guidance

DirectQuery for Power BI Datasets video:
https://www.youtube.com/watch?v=ZSyYegfA6PQ