In a traditional tap,the jumper is fastened to a screw,together with a rubber washer.When you turn the tap on,the screw rises lifting the jumper and allowing the water to run out through the spout.When you turn off the tap,the jumper goes down again onto the seat,cutting off the flow of water.
In a ball tap,the ball assembly a mental ball with a hole drilled in it, is turn by a handle.When you turn the tap on, the water flows through the hole.When you turn it off, the ball assembly turns and cuts off the flow of water.
In a single lever tap,the ball assembly is hollow with 3 holes, cold and hot water enter through these holes, and the mixed water flows out through the third one. When the tap is turned off, the position of the ball does not allow cold or hot water to enter.When you turn the lever right and raise it ,the hole with the bule rim is adjusted for the cold water pipe,so cold water flows into the ball.When you turn the lever left and raise it,the wave for cold water is cut off,but the hot water can flow into the ball.When you raise the lever in the middle,both cold the hot water can flow through the tap .