What are the differences between a UIView and a CALayer?

Question

Both have most of the same attributes, both support different kind of animations, both represent different data. What are the differences between a UIView and a CALayer?

Answer 1

UIView: Views have more complex hierarchy layouts. They can receive user interactions like taps, pinches, cliks and more. Working with UIViews happens on the main thread, it means it is using CPU power.

CALayer: Layers on other hand have simpler hierarchy. That means they are faster to resolve and quicker to draw on the screen. There is no responder chain overhead unlike with views. Layers are drawn directly on the GPU. It happens on a separate thread without burdening the CPU.

For more details: https://medium.com/@fassko/uiview-vs-calayer-b55d932ff1f5