CNG (Compressed Natural Gas), LPG (Liquified Petroleum Gas), and LNG (Liquified Natural Gas) are all types of fuels used for transportation and cooking. CNG is derived from natural gas, while LPG is derived from petroleum and LNG is derived from natural gas. All three types of fuel are stored in a compressed, liquefied form for safety and convenience. CNG and LPG are both used in cars, buses and trucks, while LNG is mostly used in large vehicles such as ships. All three can be used for cooking as well.