Compressed Natural Gas (CNG) buses are public transportation vehicles that run on natural gas instead of diesel or gasoline. They use a fuel system that compresses natural gas to a high pressure, allowing it to be stored in tanks on the bus. This type of fuel is considered cleaner, producing fewer emissions and pollutants compared to traditional fuels. CNG buses are becoming increasingly popular in many cities due to their environmental benefits and lower operating costs. They can help reduce air pollution and greenhouse gas emissions, contributing to a more sustainable public transport system. Additionally, CNG is often less expensive than diesel, making it an economical choice for transit agencies.