Splines are mathematical curves called nonuniform rational B-splines (NURBS) that can be used to make organic shapes in AutoCAD. An example of a drawing made with a spline is this top view of a mouse. Making this shape with regular draw tools, such as Circle, Arc, and Line, will be difficult, as shown:
Figure 3.53: A simple top view of a computer mouse made with the spline tool
In AutoCAD, there are two ways of making spline. They are spline fit, which is defined by the fit points, and spline control vertice (CV), which is defined by the CVs or control vertices that act as a frame for the curve.