Importance of Cocos2D CCScenes? - ios

Question

I recently followed Ray Wenderlich's Cocos2D tutorial for putting Cocos2D in a UIKit app. I am currently only using Cocos2D in only one of my UIViews. In the tutorial he uses a CCScene which is a specific .h and .m class in the project. In the scene is some code which I do not know the important of either. I must say that I am new to Cocos2D and I am wondering what is the point of a CCScene? Do I need to use it in my situation? And if so, how?
Thanks!
Edit1: Is this correct? I am also adding a simple game loop so should I do it in the way I am doing it below or should I use CADisplayLink?
//Cocos2D methods
-(id) init {
if((self=[super init]))
{
CCScene *scene = [CCScene node];
CCLayer *layer = [CCLayer node];
[scene addChild:layer];
[[CCDirector sharedDirector] runWithScene:scene];
[self performSelector:#selector(cocosgameLoop:) withObject:nil afterDelay:1/60.0f];
}
return self;
}
- (void)cocosgameLoop:(ccTime)dT {
//Check for collisions here and add gravity, etc....
}
- (void)viewDidUnload {
[super viewDidUnload];
[[CCDirector sharedDirector] end];
}
//

Answer 1

CCScene is a root node in a scene graph. A node that have no parents. CCDirector operates with CCScenes only. Read this for more information: http://www.cocos2d-iphone.org/wiki/doku.php/prog_guide:lesson_3._menus_and_scenes
ANSWER TO YOUR COMMENT
Actually you don't have to understand how CCScene is implemented. But if you want something to be rendered with cocos2d you have to create a CCScene and pass it to CCDirector. The common way is:
CCScene *scene = [CCScene node];
CCLayer *layer = [CCLayer node];
[scene addChild:layer];
[[CCDirector sharedDirector] runWithScene:scene];
Usually you have to subclass a CCLayer and reimplement init method to add your staff (sprites for example). Take a look at programming guide for more more detailed answer:
http://www.cocos2d-iphone.org/wiki/doku.php/prog_guide:index