Postoperative pathology reports of tumor patients often have the words hypo- and hyper-differentiated, both of which are descriptions of the tumor condition. If the tumor cells and tissues are close to normal and the tumor is well differentiated, the pathological histological grading is highly differentiated, on the contrary, almost losing the morphology and tissue structure of normal cells, it is hypodifferentiated or undifferentiated. Usually, highly differentiated tumors grow and spread slowly, which is also commonly referred to as low malignancy. On the contrary, hypodifferentiated and undifferentiated tumors grow and spread rapidly and have a high degree of malignancy. Tumor differentiation is generally divided into four levels: highly differentiated, moderately differentiated, hypodifferentiated and undifferentiated. Hypofractionation and hyperfractionation are mainly pathological histological grading concepts, which describe the degree of abnormality of cancer cells and tissues or the degree of difference from normal cells, and reflect the index of tumor growth and spread rate, and simply represent the magnitude of tumor malignancy. Knowing the correct cancer grading helps doctors to formulate treatment plans and can determine the probability of recovery or recurrence of patients.