Electromagnetic trains that use magnets are using Electromagnetic suspicion (Ems). Electromagenetic magnets are just magnets that use electricity and can be tured on and off.
How does the train go so fast?
The reason the train goes so fast is because there is less friction between the ground and its wheels. This is becaue the magnets are levitating the train.
How it work
It uses the magnets to push it up and then uses the magnets to propel it.
It uses the south and north poles to keep it on the tracks but then it uses both to nrrorth and south to south to levitate it. It uses both and south and north (because opposites attract) to propel the train.