ToolTip versus Popup (WPF control)

Question

What are the main differences between these WPF controls?
And when I should use a ToolTip instead of Popup?

Answer 1

A ToolTip is a small pop-up window that appears when a user pauses the mouse pointer over an element; the Popup control provides a way to display content in a separate window that floats over the current application window relative to a designated element or screen coordinate.

A Popup does not automatically open when the mouse pointer moves over its parent object. If you want a Popup to automatically open, use the ToolTip or ToolTipService class.

For more information see: ToolTip overview and Popup overview.