NURBS models, or Non-Uniform Rational B-Splines, are mathematical representations used in computer graphics to create smooth and flexible shapes. They allow for precise control over curves and surfaces, making them ideal for designing complex objects in industries like automotive and animation. These models use control points, weights, and knots to define their shape, enabling designers to manipulate the geometry easily. NURBS are widely used in software applications such as AutoCAD and Rhinoceros, providing a powerful tool for both 2D and 3D modeling.