How are "Layers" used in Unity?

In Unity, layers serve a crucial purpose for organizing GameObjects, particularly for rendering and collision detection. When you assign GameObjects to specific layers, you can control how they interact with each other within the physics system and the rendering pipeline.

For instance, layers allow you to specify which GameObjects should be rendered by the camera or which ones should interact in collision detection. This is particularly beneficial in a complex scene with many objects, as it helps optimize performance and enhances workflow. By segregating objects into different layers, developers can manage visibility, culling, and how physics interacts between objects, making it easier to implement features such as environmental effects, enemy AI, and gameplay mechanics.

Using layers effectively allows for more efficient scene management, as it reduces the computational workload when checking for collisions or rendering the scene, helping to maintain smooth performance even with numerous GameObjects present.