A shaft transmits power from one part to another. It can receive, transmit, or both receive and transmit power. Shafts are usually circular and made of metal. There are two main types of shafts: transmission shafts, which transmit power between machines, and axle shafts, which support rotating wheels. Shafts have advantages like strength and durability but also disadvantages like potential vibrations and noise. Shaft design considers factors like required torque, strength, and rigidity. Materials and manufacturing processes are selected based on the shaft's intended use and stresses.