bubble help
In a computer user interface, bubble help is text information that is displayed in a small balloon or box when a computer user moves the mouse cursor over a selected user interface element, such as the iconic items in a task bar. The box (or "bubble") is usually timed to disappear after a few seconds.
When developing a user interface with bubble help, a programmer writes code that tells the size and background color of the box, the text message to display, and when it should be removed. Bubble help is provided in most Microsoft applications, including Access and Word.