A dialog box in Excel is a screen where you enter information and make choices about various aspects of the current worksheet or its contents, such as data, charts, and images.
Using Dialog Box Launchers in Excel
One way to open dialog boxes is to use the dialog box launcher. The launcher is a small downward-pointing arrow located in the lower-right corner of individual groups or boxes on the ribbon.
Examples of groups with a dialog box launcher are:
Not all dialog box launchers in Excel are in the corner of ribbon groups. Some, such as those under the Formulas tab, are linked to separate icons on the ribbon.