Tooltip

< System development
 * Wikipedia: https://en.wikipedia.org/wiki/Tooltip

Introduction

 * The tooltip or infotip or a hint is a common graphical user interface element. It is used in conjunction with a cursor, usually a pointer. The user hovers the pointer over an item, without clicking it, and a tooltip may appear—a small "hover box" with information about the item being hovered over.
 * Microsoft also uses the term: "Screentip".

Examples
In the screenshots below you can find some examples of how to add extra information in an application.