Taoism encompasses a wide range of practices from martial and healing arts, to yoga and meditation, to poetry, painting, calligraphy and geomancy, as well as methods for working with the Five Elements. All of them are ultimately contained within the teachings of the I Ching (Book of Changes). Although throughout the ages some Taoists have studied all aspects of Taoism, most certainly do not. Instead, each individual attunes to their path to what is relevant to their personal and spiritual development. That said there are core techniques which all Taoists train. They can be classified in three categories: the 16 nei gong, Five Element practices and I Ching arts.