The above description is commonly found in Google. It defines in face value the 24 mountains of the SanYuan Earth Plate. More important it can be grouped and defined with its respective YinYang as the followings: -
4 Graves, 4 Baths and 4 Stables are referred to the 12 growth phases. Stables are referred to Sickness or the Horse positions. The 4 Yang Stems and 4 Yin Stems together with the 4 Ordinal Gua complete the 24 mountains.
FENGSHUI BASICS - YINYANG OF THE SANYUAN 24 MOUNTAINS