problem with animation? or unity?

hi i didnt know if i should publish here or on animation forum, anywaway i have a problem and i can assign a animation in a

    public Animation cen;

a clip https://gyazo.com/7faddd65057bbe5987d189f64eaaca18

From the video clip, you are trying to serialize an AnimationClip (Unity - Scripting API: AnimationClip), not an Animation.

what the difference ? ty anywayi did public AnimationClip cen;

and why cen.play is not working .-.

Animation is the Component that lives on the Gameobject and plays the animation clip supplied.
You need a reference to the Animation component and assign the animation clip that you have referenced via the public variable to it.
Then you can play the Animation via the Animation Component.