What is the purpose of adding a custom column in Power Query Editor?

Adding a custom column in the Power Query Editor allows you to perform calculations based on existing columns within your dataset. This feature is particularly powerful because it enables users to manipulate data in a variety of ways, creating new values derived from current data. For example, you might want to combine two text fields into one, calculate the difference between two numerical fields, or apply conditional logic to derive a new column based on the values of other columns.

When you create a custom column, you can use a formula or a set of defined transformations to achieve your desired outcome. This capability is essential for preparing your data for analysis, as it allows you to tailor the dataset to fit the specific analytical needs of your reports and dashboards.

The other options involve important operations in Power Query but do not specifically pertain to the purpose of a custom column. Enhancing visual representations refers to features available in the reporting layer rather than during data transformation. Removing unnecessary columns focuses on data cleaning and preparation, which is a different task, and connecting to external data sources concerns the initial stage of data integration rather than modifying existing data.