What does "tagging up" mean in NCAA softball?

The concept of "tagging up" in NCAA softball specifically refers to the rule that when a fly ball is caught, runners on base must return to their original base and retouch it before they can advance to the next base. This rule is in place to ensure that the runners do not gain an unfair advantage by leaving the base too early while the ball is in the air. Therefore, if a runner fails to retouch the base after the ball is caught and tries to advance, they can be put out if the defense tags them or the base they left. This is crucial in maintaining the integrity of base running during fly balls, making it essential for runners to understand and follow this rule to avoid being called out.