Shaders are small programs used in computer graphics to determine how surfaces appear in a scene. They control the color, brightness, and texture of objects, making them look realistic or stylized. Shaders are essential in video games and movies, as they help create effects like shadows, reflections, and lighting, enhancing the overall visual experience. There are different types of shaders, such as vertex shaders and fragment shaders. Vertex shaders handle the shape and position of objects, while fragment shaders focus on the final color of each pixel. Together, they work to bring life to 3D models and environments, making them visually appealing and immersive.