Cubic splines are a type of mathematical function used to create smooth curves through a set of points. They consist of piecewise cubic polynomials, which means that each segment of the curve is defined by a cubic equation. This allows for flexibility in fitting the curve to the data while ensuring that the overall shape remains smooth and continuous. In applications like computer graphics and data interpolation, cubic splines help in generating natural-looking curves. They are particularly useful in scenarios where precise control over the curve's shape is needed, such as in animation, CAD software, and data visualization.