1-Open circulatory system :primary found in invertebrates. Here, the blood flows freely through cavities to conduct the blood.
2-closed circulatory system :is found in Vertibreats and a few invertebrates like a earthworms.
This system has the presence of vessels that conduct blood throughout the body.
When blood or any other body fluid flows throughout the body through blood vessels(arteries, veins and capillaries then type of circulation is called closed type of circulatory system.
Whereas, when blood flows throughout the body cavity and all the body tissues are bathed in it then the type of circulation is called is open type of circulatory system.