This was very interesting to me because I have seen one before. It is also called a monorail. I saw one in Disney World while on vacation there. I found information about what a third rail is. It is a raised rail that provides electric power to electric trains.
Electric trains are trains that run by electricity and are guided by a cable overhead.
It runs on a track like all other trains. One last fact that I learned is what an underwater train was. I found it in a book. The legs of this electric train were 7 meters high so that it wouldn't hit the sea. It is also called Daddy Longlegs.