Cameras are a critical game object in our Unity games. They allow the player to see the game environment. Unity works diligently during gameplay to render objects within a camera's frustum. Graphics rendering can represent a tremendous performance issue. It is therefore important that we pay special attention to our camera's occlusion culling parameter. When enabled, Unity will not render objects that are occluded, or not seen by the camera. An example would be objects inside a building. If the camera can currently only see the external walls of the building, then none of the objects inside those walls can be seen. So, it makes sense to not render those. We only want to render what is absolutely necessary to help ensure our game has smooth gameplay and no lag.