Hematology examines blood, blood-forming organs, and the disorders that affect them. It investigates the biology of red and white blood cells, platelets, bone marrow, and the coagulation system, as well as how disruptions in these components lead to anemia, clotting disorders, leukemias, lymphomas, myelomas, and other hematologic diseases. The field integrates molecular genetics, immunology, pathology, and clinical medicine to improve diagnosis, monitoring, and treatment—from transfusion medicine and anticoagulation management to targeted therapies and stem-cell transplantation. Hematology underpins essential advances in both fundamental biology and patient care across a wide spectrum of conditions.