Literally, it means encouraging and cheering, but when it is used in competitions, it means cheering (the domestic slogan is cheering), which has the function of boosting morale and inspiring people. Cheerleading, called "Cheerleading" in English, refers to the group that cheers for the competition, so cheerleading is a group activity.
It depends on the rhythmic music that can strongly cheer people who want to cheer.
For example, the China cheerleading song "We Will Win"