A muffler is a part of the exhaust system that reduces the noise created by engine exhaust gases. When an engine runs, hot gases leave the combustion chamber at high speed.

The terms muffler and exhaust are often used as though they mean the same thing. In motorcycle terminology, the exhaust is the complete system that carries gases away from the engine, while the muffler is one component within that system.

​A motorcycle muffler is an essential part of the exhaust system that shapes sound, controls airflow, and contributes to overall riding comfort. Although many riders recognize it mainly by the exhaust tone, the muffler performs several important mechanical functions.