Dodson's Law is a principle that describes the relationship between arousal and performance. It suggests that performance improves with increased arousal, but only up to a certain point. Beyond this optimal level of arousal, performance can decline due to stress or anxiety. This concept is often illustrated with a curve, known as the Yerkes-Dodson Law, which shows that moderate arousal leads to the best performance. This law is applicable in various fields, including sports, education, and psychology, helping to understand how emotional states can influence effectiveness in tasks.