Blood is the liquid that circulates in the blood vessels. Blood consists of blood cells and plasma. The difference between blood and plasma is as follows: First, the color is different. Blood is red because it contains red blood cells, while plasma is the remaining liquid after whole blood is separated from blood cells, and its color is light yellow. Second, their specific gravity is different, because blood contains blood cells, the ratio of blood is higher than the specific gravity of plasma. Third, their functions are different. Since blood contains various blood cells, they have the function of transporting oxygen, stopping bleeding and immunity. Plasma, on the other hand, has no blood cells, so it has no oxygen transport, hemostasis, or immune function. So there is a clear difference between blood and plasma, but blood contains plasma, and plasma does not have various blood cells in it.