Relation between Camera & Scene

I wonder whether the camera has only one scene binding?

The camera Created through scene as follow:
cameraNode = scene_.CreateChild(“Camera”);

But the when create viewport,It need pass scene & camera as follow:
Viewport@ viewport = Viewport(scene_, cameraNode.GetComponent(“Camera”));

if I use another scene with the same camera : Viewport@ viewport = Viewport(sceneTest, cameraNode.GetComponent(“Camera”))
it still work!