What is the difference between turning and milling operations?

In turning, the workpiece rotates while a stationary cutting tool removes material, primarily used for cylindrical parts on lathes. In milling, the cutting tool rotates while the workpiece is stationary or moves linearly, used for flat surfaces, slots, and complex contours. Turning is for axisymmetric parts like shafts and bushings, while milling handles prismatic parts, pockets, and 3D surfaces.