The train experiment that was demonstrated on the video uses the concept known as “Electromagnetism”. Magnets has always been around and we are all accustomed that they have 2 poles called the North and South. These poles are responsible for magnetic field around a magnet. These magnetic field is technically a push and pull force. The North Pole produces the push force and the South Pole pulls the force. Thus magnets of the opposite poles attract when attached together and they repel if attempted to face the same poles.