Tween - It is the basic action of the animations in Flash. It allows us to move a Flash symbol from one place of the stage to another, being necessary only two frames, which optimizes a lot movie performance
3 Types of Tween
Classic tween
Motion tween
Shape tween
Classic tween - is applied to a single object and allows animation between two different colors and shapes.
Motion tween – is tweening a symbol movement one position to another.
Shape tween – enables you to animate an object from one shape to another.