Brain tumors are cancerous or non-cancerous growths of abnormal cells in the brain. They may either start in the brain or spread to the brain from elsewhere in the body.
There are two main types of tumors:

Noncancerous (benign): Slow growing tumors that do not spread to other parts of the body.

Cancerous (malignant): Faster growing tumors that are more difficult to treat, and usually destroy the surrounding brain tissue.

• Primary tumors originate in the brain and rarely spread throughout the body. They are named from the cells in which they originated, such as astrocytomas, oligodendrogliomas and ependymomas.
• Secondary brain tumors (or brain metastases) originate from cancer cells in another part of the body and spread to the brain.