Cancer can be categorized in several ways, based on different criteria. Here are some of the major categories:

1. Carcinoma: This is the most common type of cancer, originating in the skin or tissues that line or cover internal organs. Subtypes include adenocarcinoma, basal cell carcinoma, squamous cell carcinoma, and transitional cell carcinoma.
2. Sarcoma: These cancers arise from bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Examples include osteosarcoma (bone) and chondrosarcoma (cartilage).
3. Leukemia: These are cancers of the blood or bone marrow characterized by an abnormal increase of white blood cells. Types include lymphocytic leukemia, chronic lymphocytic leukemia, acute myeloid leukemia, and chronic myeloid leukemia.
4. Lymphoma and Myeloma: Lymphomas are cancers that begin in the lymph nodes and immune system tissues. Myeloma is cancer of plasma cells in the bone marrow.
5. Central Nervous System Cancers: These cancers develop in the brain and spinal cord. Examples include glioma, meningioma, and brain stem glioma.

Each of these categories has different subtypes, and within each subtype, individual cancers can vary significantly in their characteristics and behavior. The treatment and prognosis for each type can vary widely based on a number of factors.