Objective-C getter/ setter

I'm trying to work my way through an Objective-C tutorial. In the book there is this example:

@interface
{
 int width;
 int height;
 XYPoint *origin;
}
@property int width, height;

I thought, "hey there's no getter/setter for the XYPoint object. The code does work though." Now i'm going maybe to answer my own question :).

I thinks its because "origin" is a pointer already, and whats happening under the hood with "width" and "height", is that there is going te be created a pointer to them..

Am i right, or am i talking BS :) ??

I just dont get it. here's main:

#import "Rectangle.h"
#import "XYPoint.h"
int main (int argc, char *argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    Rectangle *myRect = [[Rectangle alloc] init];
    XYPoint *myPoint = [[XYPoint alloc] init];

    [myPoint setX: 100 andY: 200];
    [myRect setWidth: 5 andHeight: 8];

    myRect.origin = myPoint; 

    NSLog (@"Rectangle w = %i, h = %i",
           myRect.width, myRect.height); 

    NSLog (@"Origin at (%i, %i)",
           myRect.origin.x, myRect.origin.y);

    NSLog (@"Area = %i, Perimeter = %i",
           [myRect area], [myRect perimeter]);

    [myRect release];
    [myPoint release];
    [pool drain];

    return 0;
}

And here's the Rectangle object:

#import "Rectangle.h"
#import "XYPoint.h"

@implementation Rectangle
@synthesize width, height;

-(void) setWidth: (int) w andHeight: (int) h
{
    width = w;
    height = h;
}

- (void) setOrigin: (XYPoint *) pt
{
    origin = pt;
}
-(int) area
{
    return width * height;
}
-(int) perimeter
{
    return (width + height) * 2;
}
-(XYPoint *) origin
{
    return origin;
}
@end

What i dont understand is this line in main: myRect.origin = myPoint; I did not make a setter for it..

BTW thanks for your fast reply's