When using UIKit Dynamics, it is important to understand what UIKit Dynamics items are. Rather than referencing dynamics as views, they are referenced as items, which adhere to the UIDynamicItem protocol. This protocol defines the center, transform, and bounds of any object that adheres to this protocol. UIView is the most common class that adheres to the UIDynamicItem protocol. Another example of a class that conforms to this protocol is the UICollectionViewLayoutAttributes class.