How a model gets its data decides how it stays current.
- Import copies the data into the model. Visuals are fast, every DAX function works, and the data is as fresh as the last refresh.
- DirectQuery leaves the data at the source and queries it each time a visual loads: always current, but slower, and some DAX and transformations are limited.
- Direct Lake reads Delta tables in OneLake (Microsoft Fabric) directly, with no import refresh of the data.
In the service, an Import model needs a scheduled refresh: up to 8 a day with a Pro license, up to 48 on Premium or Fabric capacity. For large tables, incremental refresh reloads only recent rows; it needs the RangeStart and RangeEnd parameters in Power Query.
A gateway is needed when the service must reach data it can't see from the cloud: an on-premises database or a file on a local network. Cloud sources such as SharePoint Online or Azure SQL Database don't need one.