Neigong, also spelled nei kung, neigung, or nae gong, refers to any of a set of Chinese breathing, meditation and spiritual practice disciplines associated with Daoism and especially the Chinese martial arts. Neigong practice is normally associated with the so-called "soft style", "internal" or neijia 內家 Chinese martial arts, as opposed to the category known as waigong 外功 or "external skill" which is historically associated with shaolinquan or the so-called "hard style", "external" or wàijiā 外家 Chinese martial arts. Both have many different schools, disciplines and practices and historically there has been mutual influence between the two and distinguishing precisely between them differs from school to school.