Blood consists of a number of different constituents. There are white blood cells, red blood cells, platelets and so many other constituents. Fractionating this whole blood gives us different kinds of fluids that are used medically for the betterment of patients. Whole blood is basically blood as it is present in the human body.
Hence, it is blood from which none of the elements are removed. It is required in conditions like blood loss, where whole blood is lost rather than parts of it. There are other types of blood such as packed cells in which there are only concentrated red blood cells, platelets, which consists of primarily platelets.