Can you explain the differences between UIView, UIWindow, and CALayer in iOS interface development?

In iOS development, UIView, UIWindow, and CALayer are different levels of view and interface management:

• UIView is an object representing a rectangular area on the screen. It handles user event processing, hierarchy placement of subviews, and rendering of content. UIView manages its own CALayer for rendering.

• UIWindow is a subclass of UIView that represents the application's window. Usually, an app has one main window, which is the root of the UIView hierarchy. UIWindow handles events and passes them to the view hierarchy.

• CALayer is a low-level object responsible for visual display and animation. Each UIView contains a CALayer that handles drawing, shadows, masks, and animations. CALayer does not handle events and does not participate directly in the view hierarchy.

Summary:

• UIView — an interface element managing interaction and layout.
• UIWindow — the root window containing UIView.
• CALayer — a graphic layer providing rendering and animation for UIView.