There are several types of hobbing machines used in manufacturing, including vertical hobbing machines, horizontal hobbing machines, and worm hobbing machines. Vertical hobbing machines are used for cutting gears and splines, while horizontal hobbing machines are used for cutting larger gears and shafts. Worm hobbing machines are used for cutting worm gears, which have a unique helical shape. Each type of hobbing machine has its own advantages and is used for specific applications in manufacturing.