Exhaust gas is a common term used to describe the byproduct of combustion engines. This gas is released from vehicles, power plants, and other sources of fuel combustion. However, there are many synonyms for this term, such as emissions, exhaust fumes, engine exhaust, and tailpipe emissions. These terms are often used interchangeably to refer to the same thing. Other synonyms include flue gas, smoke, and effluent. It is especially important to monitor these gases, as they can have harmful effects on the environment and public health. Therefore, measuring and reducing exhaust gases is a critical area of concern for many industries and communities.