Lymphoma is a type of blood cancer that develops from the lymphocytes, whereas a lymphocyte is a type of White Blood Cell (WBC). The growth of tumors in the lymphocytes causes lymphoma. The tumors affect the blood, lymph nodes, thymus, bone marrow, and lymphatic system. There are many subtypes of lymphoma, but lymphoma is the most commonly divided into two types, Non-Hodgkin's lymphoma (majority of cases) and Hodgkin’s lymphoma. The two types are mainly divided based on how they develop, spread, and are treated.