Shaders are small programs used in computer graphics to control how objects are rendered on the screen. They help create effects like lighting, shadows, and colors, making images look more realistic or stylized. Shaders run on the graphics processing unit (GPU), allowing for complex visual effects without slowing down the main computer processor. There are different types of shaders, including vertex shaders and fragment shaders. Vertex shaders handle the position and shape of objects, while fragment shaders determine the color and texture of each pixel. Together, they work to bring life to video games, movies, and other digital media, enhancing the overall visual experience.