It is very important to understand the concept of motion tweening in Flash. Motion tweening is used to automatically alter the properties of a symbol (a movie clip, a button or a graphic) over a certain length of time. Motion tweening can be use to change the _x and and _y property of an element on the stage, the alpha transparency, the size of the symbol, the tint ...etc let's start with a basic tutorial that will help us to understand the very basic of motion tweening.