A shadoof is like a big see-saw. It has a long stick that goes across a fulcrum, or support, in the middle. On one side of the stick is a container, like a bucket or basket, and on the other side is a weight, like a rock or a big block.
People use the shadoof to lift water out of a well or a river. They scoop up some water from the well or river and dump it into the container on the shadoof. Then they push down on the end that has the weight, which lifts up the end with the water. They keep pushing until the water tips out into a channel, ditch, or irrigation canal.
It takes a lot of work to lift the water this way, but it's a method that has been used for thousands of years to get water to crops and other places where it's needed.