To streamline information processing work by streamlining reference to explanatory information about function icons.

When a button of a pointing means is operated while a pointing cursor moved with the pointing means points a function icon displayed in an application window, an operation selection window including a function operation list and "Explanation" of the function icon is displayed on the display device. When another button is operated while the pointing cursor moved with the pointing means points "Explanation" in the operation selection window, an explanatory information window describing function explanations for the function icon is displayed on the display device.