what is Xingyi quan ？

Xingyi quan, which translates to "Form-Intention Fist" or "Mind-Body Boxing," is a Chinese internal martial art known for its direct, aggressive, and explosive movements. It is one of the three main internal Chinese martial arts and is characterized by using coordinated whole-body actions to generate powerful bursts of force. The core of the style is based on the Five Elements (Metal, Water, Wood, Fire, Earth) and often incorporates animal-based movements. 
Key characteristics
Internal martial art: It focuses on the harmonious combination of mind and body to generate power, which is different from external styles that often focus on speed and strength alone.
Direct and aggressive: Xingyiquan is known for its no-nonsense, aggressive approach. Practitioners aim to close the distance with an opponent quickly and use powerful, explosive movements.
Five Elements: The style is built around five fundamental "fists," each representing one of the five elements and a corresponding martial principle.
Power generation: Power is generated from the ground and travels up through the body, creating bursts of force. This is sometimes compared to the power of a spear, but adapted for empty-hand fighting.
Focus and simplicity: The style's simplicity allows students to focus on the essence of combative strategy rather than memorizing countless techniques. 
Synonyms and alternative names
Form-Intention Fist
Mind-Body Boxing
Hsing I Ch'üan
Hsing I
Xingyi 
Usage examples
Martial application: The most common use is as a direct, powerful fighting style designed to quickly overwhelm an opponent.
Health benefits: Training is also practiced for its health benefits, with certain movements believed to aid in lung and spinal health, as well as benefiting the kidneys.
Personal development: Many practitioners use it as a mind-body practice for overall health, coordination, and focus.