What is the difference between "benign" and "malignant" tumors?

A benign tumor is a non-cancerous growth that does not invade surrounding tissues or spread to other parts of the body. Benign tumors are usually well-defined, encapsulated, slow-growing, and rarely life-threatening unless they compress vital structures. A malignant tumor is cancerous, capable of invading adjacent tissues and metastasizing to distant organs through the blood or lymphatic system. Malignant tumors grow rapidly, lack clear borders, and are life-threatening if untreated.