Exhaust clamps and hangers are used to connect and suspend the exhaust system components under the body of the vehicle.
Exhaust Hangers. As the engine runs, it vibrates, so the hangers have flexible rubber components to compensate for movement. If the exhaust system was connected solidly, stress cracks would develop.
Exhaust Clamps. Exhaust clamps, usually a type of U-bolt, connect the exhaust pipes to the muffler and catalytic converter. On most new exhaust systems, welds instead of clamps are used.