Which Excel feature allows you to automatically fill cells with a series of values?

The feature that allows you to automatically fill cells with a series of values is AutoFill. This functionality in Excel enables users to drag the fill handle—an iconic small square at the bottom-right corner of a selected cell or range of cells—across adjacent cells to populate them with a series of values based on a pattern found in the initial cells. For example, if you start typing the days of the week or a sequence of numbers, such as 1, 2, 3, and then drag the fill handle down, Excel will recognize your pattern and continue it automatically in the subsequent cells.

While the fill handle is the tool you physically use to perform the action, it is the AutoFill feature that encompasses the behavior of filling in the values according to the specified pattern or series. Other choices like the Series Tool or Value Series are not standard names for features available within Excel, making them less relevant in this context. This clarity about features helps users effectively utilize Excel for tasks that require sequential data entry or pattern recognition.