John Dutton from the University of Alaska at Fairbanks Physics Department explains that magnetic levitation works by utilizing the magnetic force during interaction of magnetic fields underneath objects to achieve floatation. This repulsive or attractive force is the same force that is experienced when two magnets are placed together.
Nick Presson at Rogers State University explains magnetic levitation in emerging technologies: In MagLev systems, high-speed transportation systems utilize the principle of magnetic levitation. Two types of suspension systems are common: electromagnetic suspension, or EMS, and electrodynamic suspension, or EDS.
Electromagnetic suspension uses attraction to levitate the MagLev train. Conventional electromagnets are placed on a pair of structures underneath the train. These structures wrap around the sides of the guideway or train track. The magnets lift the train using the attraction towards the laminated iron rails of the guideway or track. This system requires constant supervision and adjustment by computers to maintain the distance between the guideway and the train.
Electrodynamic suspension uses the repelling force to achieve levitation. These systems use super-cooled superconductors. The induced supercurrents produce mirror images of the poles when a magnet is brought close to the superconductor, thereby producing a repelling force that levitates the magnet. A cylindrical tank holds liquefied helium and nitrogen, which cool the superconducting coil in the rails. The chilling of the coils to frigid temperatures in these systems saves more energy than the electromagnetic-suspension process does.