Haematology and hematology are both terms used to describe the study of blood. Haematology is the British spelling, while hematology is the American spelling. Both terms refer to the same field of study, which involves the examination of the structure, function, and diseases of the blood. This includes studying the components of the blood, such as red and white blood cells, platelets, and plasma, as well as the organs and tissues that produce them. It also involves studying the effects of blood-related diseases, such as anemia, leukemia, and hemophilia.