How do natural gas heaters work?

It is not a different kind of fossil fuel resource, except that it can be generated by anaerobic processes from waste materials much more quickly than petroleum or coal. See also https://tutor.hix.ai for a detailed description of natural gas heating systems. "Natural gas" is primarily methane, so it produces less carbon dioxide per energy unit release than other hydrocarbons.

Natural gas heaters work by burning natural gas to produce heat. The gas is ignited by a pilot light or an electronic ignition system. The heat generated from burning the gas is then transferred to the surrounding air either directly or through a heat exchanger. The heated air is then circulated throughout the space by a fan or blower, raising the temperature and providing warmth. Some natural gas heaters may also have thermostats to regulate the temperature and ensure efficient operation.