• There is a very strong relationship between the view and its layer
• View derives most of its data from the layer object directly
• There are also standalone layers

If you change almost any property of a standalone layer, it will make a brief animation from the old value to the new value. However, if you change the same property of a view’s layer, it just changes from one frame to the next. Despite it being layers involved in both cases, the default layer behavior of implicit animations doesn’t apply when the layer is attached to a view.

The UIView class disables layer animations by default but reenables them inside animation blocks

Views always have an underlying layer.