An anti-rolling gyro is like a toy top that can keep a boat or a ship steady. When you spin a top, it stays upright and doesn't tip over because of its spinning motion. The anti-rolling gyro does the same thing, but it's much bigger and stronger.
Imagine you're on a big boat and the waves are making it move up and down and side to side. This can make you feel dizzy or even sick! But if the boat has an anti-rolling gyro, it can help to reduce that up and down and side to side motion. It works by spinning around really fast and creating a force that keeps the boat from rolling over.
This is important because when boats roll too much, the crew and passengers can get hurt, and things on the boat can break. By having an anti-rolling gyro, the boat can stay steadier, and everyone can enjoy a smoother ride.