section_path: Types and terminology
section_name: Types and terminology
paragraph_text: Types and terminology
  
  Trains can be sorted into types based on whether they haul passengers or freight (though mixed trains which haul both exist), by their weight (heavy rail for regular trains, light rail for lighter transit systems), by their speed, by their distance (short haul, long distance, transcontinental), and by what form of track they use. Conventional trains operate on two rails, but several other types of track systems are also in use around the world, such as monorail.