Where can you find a layer in iOS development?

CALayer: The basic building block for visual content on the screen. Each UIView has its own layer (layer) that manages appearance, animation, and sublayer hierarchy.

CAShapeLayer: Used for drawing vector shapes. Defines outlines, fill, and stroke based on CGPath.

CATextLayer: Displays formatted text. More efficient for displaying text than UILabel, especially when rendering large amounts of text or in animated views.

CAGradientLayer: Draws a gradient fill. Allows smooth transitions between multiple colors.

CAReplicatorLayer: Creates multiple copies of its sublayers, applying transformations to them.

CAScrollLayer: Provides a scrollable viewport for its sublayers.

CATiledLayer: Divides a large image into tiles for more efficient rendering of large content.

CAEmitterLayer: Creates and animates particle systems, for example, to simulate smoke, fire, or snow.

In animation: Layers are used to create explicit (CABasicAnimation, CAKeyframeAnimation) and implicit animations, as well as to define properties that can be animated.

In Core Image: Core Image filters work with image data, often represented as layers.

In SceneKit: 3D scenes consist of nodes that contain geometry and materials, linked to rendering that is performed using layers.

In SpriteKit: 2D graphics in SpriteKit are organized into nodes, which are essentially lightweight layers.

In AVFoundation: Video content can be displayed using AVPlayerLayer, which is a subclass of CALayer.