Bosu Ball (also called half balance ball) is a transliteration of Bosu Ball.
Originated in the field of yoga rehabilitation, the full name of bosu is "Both Side Up", which uses special equipment to exercise the body's sense of balance and other sports abilities, and the half ball is undoubtedly this special equipment. It is derivative equipment.
The half ball is essentially a half-sized stability ball that is placed on the ground.
To perform the exercise, you will need to stand with one foot on the half ball and the other foot on the ground. From this position, you will need to try to maintain your balance while keeping your feet in place.