B-splines, or basis splines, are a type of piecewise polynomial function used in computer graphics, data fitting, and numerical analysis. They provide a flexible way to represent curves and surfaces by combining multiple polynomial segments, ensuring smooth transitions between them. B-splines are defined by control points, which influence the shape of the curve without necessarily lying on it. One of the key advantages of B-splines is their ability to maintain local control, meaning that moving a control point affects only a portion of the curve. This property makes them useful in applications like CAD (Computer-Aided Design) and animation, where precise adjustments are often needed.