VML

VML is a language for defining graphical objects in cases where DrawingML does not apply in Office Open XML, such as text boxes and shapes in WordprocessingML and comments and controls in SpreadsheetML.

VML is a legacy format originally introduced with Office 2000 and is existing mainly for backwards compatibility reasons. The DrawingML format is a newer and richer format created with the goal of eventually replacing any uses of VML in the Office Open XML formats.