What distinguishes a calculated field from a table calculation in Tableau?

The distinction between a calculated field and a table calculation in Tableau is fundamentally rooted in their creation and functionality. A calculated field is created at the data source level and is used to define new data fields based on existing data columns. It allows users to perform computations that can be reused across various visualizations, making it an integral part of the data preparation phase.

In contrast, a table calculation operates on the results of existing visualizations and provides a mechanism for performing computations there. It works on-the-fly, adjusting to changes in the view or context without altering the underlying data source itself. This means that table calculations can only be created once you have established a visualization, as they depend on the aggregated data being displayed.

Overall, the correct option highlights that calculated fields are static definitions that become part of the dataset and can be utilized wherever the data is referenced, while table calculations rely on the visualization context for their application.