Clicking and dragging the fill handle in Excel is a powerful autofill feature that allows users to quickly copy formulas or data down a column or across a row. The fill handle is a small black dot at the bottom-right corner of a cell containing data or a formula. When you mouse over the dot, your cursor turns into a plus sign (+)—the fill handle. Clicking and dragging the fill handle to highlight the cells you wish to target, and they’ll be filled with copies of the original.

The fill handle can be used for the following purposes:

• Copying cell values
• Generating sequences
• Filling in patterns
• Copying formulas
• Duplicating/copying content of the cell(s) to multiple cells

To change how you want to fill cells, click the Auto Fill Options button that appears after you finish dragging, and pick the option that you want. There are also other ways to use the autofill command other than fill handle. For example, you can double-click the fill handle to fill in a series based on the pattern in the active cell.

In summary, clicking and dragging the fill handle in Excel is a quick and efficient way to copy formulas or data down a column or across a row. It can save a lot of time and prevent errors.