Red blood cells, white blood cells, blood platelets, and plasma, are major constituents of the blood. However, when injuries occur in the blood vessels, there is the formation of a blood clot. A blood clot is a mass of coagulated red blood cells, white blood cells, and platelets in a network of fibrin. The formation of a blood clot in the blood vessels can either be called thrombosis or embolisms depending on the nature of formation. A blood clot is produced during injuries to prevent the continuous flow of blood.
Thrombosis simply means when there is the formation of a blood clot within the blood vessels, whether an artery or a vein, to prevent the flow of blood. Embolism, on the other hand, simply means when there is the formation of a blood clot in any part of the human body when a blood clot is carried by the bloodstream from its original place to form a blockage of another blood vessel.