Stroke order (; Yale: bāt seuhn; hitsujun or kaki-jun; pilsun or hoeksun) refers to the order in which the strokes of a Chinese character are written. A stroke is a movement of a writing instrument on a writing surface. Chinese characters are used in various forms in Chinese, Japanese, Korean, and in Vietnamese. They are known as Hanzi in Chinese, kanji in Japanese, Hanja in Korean, and Hán tự in Vietnamese.