Koans are often used by Zen masters as a teaching method. They present the koan to a student, who then contemplates it during meditation. The process of grappling with a koan can lead to a sudden, intuitive understanding known as "kensho" or "satori," which are moments of enlightenment.
Examples of well-known koans include "What is the sound of one hand clapping?" or "Does a dog have Buddha nature?" The responses to these koans are not about finding the right answer but about experiencing a shift in consciousness.
Koans also serve to demonstrate the limitations of language and logical reasoning in capturing the true nature of reality. By engaging with a koan, practitioners learn to see beyond the surface of words and concepts, aiming to reach a more profound understanding of existence.