Maglev trains float above a fixed track called a guideway, but do not touch it. The train's speed is not limited by the friction or vibration that contact with a track would cause. But only low-speed maglev trains are in commercial use today.
Maglev trains have several advantages over other high-speed trains.
For example, they can reach higher speeds and operate more quietly. Their guideways need little maintenance. In addition, maglev trains use electricity for power and therefore produce little pollution themselves. Electromagnetic maglev uses magnetic attraction. Electrodynamic maglev was invented in the early 1960's by nuclear engineer James R. Powell and physicist Gordon T. Danby of the United States.