Every UIView subclass has a transformproperty that lets you manipulate its size, position and rotation using something called an affine transform. This property is animatable, which means you can make a view smoothly double in size, or make it spin around, just by changing one value.
The first one makes an image view double in size, the second one makes it move up and left 256 points, the third one makes it spin around 180 degrees (the values are expressed in radians), and the fourth one sets the image view's transform back to "identity" – this means "reset."