Flag hinges are have two square mounting plates offset from each other so that each plate can spin in a 360° rotation independently of the other. Flag hinges allow the pin to be removed so the door can be separated from the frame. They are available in left-handed, right-handed or neutral weld-on styles.
Leaf hinges consist of two rectangular plates connected by a pin through a centre barrel. Free swinging leaf style are easily swung open and closed, offering no resistance, and are the most common type of hinge and you need to go no further than a door of your home or office to see one in use.