Ferritin is a blood protein that contains iron and it is an important measure of levels of iron storage in the body because it can provide an early sign of iron deficiency. It If your level is low, it may mean you have iron deficiency. High ferritin levels can indicate iron overload but also things like inflammation, liver disease, rheumatoid arthritis or thyroid disease. 

Iron is an important mineral that is involved in red blood cell metabolism and oxygen transport. Iron studies are used to identify iron deficiency or overload states. 

Total iron binding concentration measures the blood's ability to attach itself to iron and transport it around the body. If you have iron deficiency (a lack of iron in your blood), your total iron binding capacity may be high. 

Transferrin is a protein found in the blood that transports iron through the blood to various tissues such as the liver, spleen, and bone marrow. When your body's stores of iron run low, your liver produces more transferrin to get more iron into your blood. The result of this is that your transferrin becomes less saturated with iron and this is why a low level of transferrin saturation can mean that you are suffering from iron deficiency. 

Unsaturated Iron Binding Concentration (UIBC) is the amount of transferrin that is reserved for the iron transportation. Iron is used for the transportation of oxygen in the blood. A high unsaturated iron binding concentration may indicate iron deficiency but it can also be increased in pregnancy and with the use of oral contraceptives. A low unsaturated iron binding capacity may occur if someone has malnutrition, inflammation, kidney or liver disease.