What is the difference between martial arts and kung fu

Wushu: the technique of punching and using weapons, a traditional Chinese sport. (Modern Chinese Dictionary) Wushu, also known as national art or martial art, is a traditional Chinese sport .

Chinese Kung Fu, also known as Chinese Wushu, is a traditional Chinese sports program that focuses on both internal and external training with the main content of technical combat and the form of exercise of sets and combat, and is a valuable cultural heritage accumulated by the Chinese people over a long period of time.

This is the answer in Baidu, from which it can be seen that kung fu has a wider scope than martial arts.