What is a calculated column in Power BI?

A calculated column in Power BI is defined as a column that is added to a table using a DAX (Data Analysis Expressions) formula. This means that the values in a calculated column are computed based on existing data in the same row and can leverage any of the other columns in that table for its calculations.

When you create a calculated column, it is stored in the model and computed at the row level for each entry, providing a way to derive new data that is relevant and often used for filtering or going further into data analysis. For example, you might create a calculated column to concatenate first and last names into a full name, or to calculate a sales tax based on a sales amount column. This functionality enhances the data model by allowing for greater analysis capabilities directly within the tables.

The other answer choices don't accurately define a calculated column in Power BI. A line that separates different data segments is more related to visuals or formatting within reports. A visual representation of data pertains to charts or graphs rather than calculated fields within the data table. Meanwhile, a temporary data storage solution does not encapsulate the permanent nature of how calculated columns function within the Power BI data model.