If you created an intricate setup inside Unity and you wish to use it inside another scene (or if your programmer wants a Prefab), you can create a Prefab.
Anything that lives in the Project Panel is basically a Prefab. Changes done to a Prefab will propagate into the instances of prefabs in the scene.
Anything that has a blue name in the Hierarchy Panel is connected to a Prefab.
Learn more about Prefabs here: http://unity3d.com/support/documentation/Manual/Prefabs.html
- Go to Assets -> Create -> Prefabs.
- Rename the Prefab that is now created in the Project Panel.
- Click and drag the object in the Hierarchy Panel to the Prefab file in the Project Panel.