One of the building blocks of a cocos2d app is the scene.Now,the question arises,What scene is?A scene is specially a node that contains any other nodes visible and is responsible for everything's running on the screen, including actions.Scenes can be transformed manually or by using actions.Your app can have many scenes, but only one of them is active at a given time.
Now,As we are aware about how important scene is ! as it is the building block of a cocos2d app,its management plays vital role in a cocos2d app.The director, CCDirector, is responsible of scene management. If you take a look at your AppDelegate.m file, at the end of the applicationDidFinishLaunching method you'll find:
Don't use runWithScene to change current scene, as it's to be used just for the first scene.
Everytime you replace scene, the previous scene will be deleted and any running actions stopped.
To retrieve a reference to the current scene running, use runningScene: