The terms "blood cancer" and "bone marrow cancer" are general expressions used to describe hematological cancers. "Blood cancer" is generally a more common term for acute leukemia. However, conditions such as Chronic Lymphocytic Leukemia and Chronic Myeloid Leukemia can be characterized as both blood and bone marrow cancers. Multiple Myeloma, on the other hand, is specifically defined as a bone marrow cancer due to the development of plasma cells within the bone marrow.