Magnetic Levitation
Magnetic levitation is when magnets push against each other hard enough to make an object float in the air.
Think of it this way
Two fridge magnets push apart when you flip one and press them together. Set one flat on a table and hold the other above it. The bottom magnet pushes up hard enough to make the top one float. That same push can lift a train off the ground.
Explaining magnetic levitation by grade level
Two magnets can push each other away. If you put them the right way, one magnet floats above the other. That push is strong enough to hold up a small train. The train rides on air, not on wheels.