Final answer:
Benign tumors remain localized and are not invasive, whereas malignant tumors invade and damage neighboring tissue and can form metastases in other body parts.
Step-by-step explanation:
The difference between benign tumors and malignant tumors primarily lies in their behavior and impact on the body. Benign tumors are characterized by their non-invasive nature; they remain localized, do not spread to other tissues or organs, and usually do not harm health, thus they can often be removed easily. In contrast, malignant tumors are cancerous, displaying no limits to their growth, invading and damaging neighboring tissues, and are capable of forming secondary tumors, via a process called metastasis, in other parts of the body. Biopsy is used to determine whether a tumor is benign or malignant.