Koan Talks

A kōan ( KOH-a(h)n; Japanese: 公案; Chinese: 公案; pinyin: gōng'àn [kʊ́ŋ ân]; Korean: 화두; Vietnamese: công án) is a story, dialogue, question, or statement from Chinese Chan Buddhist lore, supplemented with commentaries, that is used in Chan, Zen, Seon and Thiền Buddhist practice in different ways. The main goal of kōan practice in Zen is to achieve kenshō (Chinese: jianxing 見性), to see or observe one's buddha-nature.

Extended study of kōan literature as well as meditation (zazen) on a kōan is a major feature of modern Rinzai Zen. They are also studied in the Sōtō school of Zen to a lesser extent. In Chinese Chan and Korean Seon Buddhism, meditating on a huatou, a key phrase of a kōan, is also a major Zen meditation method.

From koan on Wikipedia