Saving derived data with full context
This is the default option, when the entire context of the derived data expression can be captured and re-used. In our earlier example, the definition of derived data includes Label, Dimensions, Measures, and Filters:
Saving derived data expression only
When selected the Expression Only option, only the expression of the base field is saved. The advantage here is that a complicated expression may be reused in any context.
In this case, the definition of derived data includes just the Label and the Measures.