Benign tumors and malignant tumors are commonly known as “cool tumors” and “hot tumors”, and some people call them “male tumors” and “female tumors”. The characteristics of benign tumor are that the tumor cells look similar to the normal cells of the tissue of origin, and grow slowly in the organ or tissue of origin, and the growth mode is “expansive growth” (expansive growth means that the tumor only has the effect of pushing and accumulating on the surrounding normal tissues), and there is an envelope separating it from the surrounding tissues with clear boundaries, and the growth is often “self-limiting”, that is, there is a certain self-restraint mechanism. As long as the surgical resection is complete, recurrence is rare. Benign tumors are less destructive to the body, unless they grow in critical areas (such as the brain) or the tumor cells can secrete a large amount of hormones, they are generally not fatal. Malignant tumors are often referred to as cancer, which are characterized by the difference between the morphology of tumor cells and the morphology of normal tissues where they occur, and the mode of growth is “infiltrative growth” (i.e. there is no obvious boundary between the tumor and the surrounding normal tissues, and there are many “crab foot-like” tumor tissues scattered in the surrounding normal tissues). Even if the tumor is surgically removed, it still has the possibility of recurrence and can run from one place to another (doctors call it metastasis). It is much more harmful to human than benign tumor and has become the main cause of human death.