The liver is divided into five lobes and eight segments: the caudate lobe, the left outer lobe, the left inner lobe, the right anterior lobe and the right posterior lobe, which are anatomically segmented and lobed according to the distribution of portal veins and hepatic veins in the liver. The segmentation is mainly from one segment to eight segments, one segment is often referred to as the caudate lobe, two segments are the upper left outer lobe, three segments are the lower left outer lobe, four segments are divided into 4A and 4B segments, 4A segment is the upper left inner lobe and 4B segment is the lower left inner lobe. The right anterior lobe is divided into the upper right anterior lobe and the lower right anterior lobe, which are the five and eight segments. Five segments are the lower right anterior lobe and eight segments are the upper right anterior lobe. The right posterior hepatic lobe is the six and seven segments, six segments are the lower right posterior lobe and seven segments are the upper right posterior lobe.