ToolTips and Control Tips Overview
Both ToolTips and control tips are short, descriptive phrases that appear when the user holds the mouse pointer briefly over a control or another part of the user interface. The difference between ToolTips and control tips is that Microsoft Outlook provides ToolTips to developers at design time, and developers provide control tips to end users at run time.
You can customize ToolTips for controls and for the Control Toolbox.
A control tip is set with the ControlTipText property. For example, use ControlTipText to set the control tip text for the Page object.