Explain the types of cancerous tumors.

(N/A) Tumors are of two types: $(i)$ Benign tumor,$(ii)$ Malignant tumor.
Benign tumors do not contain cancerous cells.
Benign tumors normally remain confined to their original location,do not spread to other parts of the body,and cause little damage.
In contrast,malignant tumors contain cancerous cells,which are rapidly proliferating cells known as neoplastic or tumor cells.
$-$ These cells grow very rapidly,invading and damaging the surrounding normal tissues.
As these cells actively divide and grow,they compete with normal cells for vital nutrients,effectively starving them.
Cells sloughed off from this tumor reach distant sites through the blood,and wherever they lodge in the body,they initiate new tumor growth.
This property of spreading cancerous cells to distant sites is known as metastasis.