Hi Muhammad89,
OK, let's stay at the irrigation system. True, the well is the supply for the system. The pump is necessary to make the system work. If you omit the pump you will have to carry the water and logically you'll require some input to do so. (no matter if good words or using a whip).
In that case the entire supply system remains unchanged because the objective is transport of water. The only change is the input which normally consists of switching advices for the pump. It has been replaced to make you carry the water.
Hope that explains it better.
The system doesn't only consist of the well, pipes and pump. There must be some kind of sensors telling an electronic control circuit that there is demand of water or the tank is full. The outputs of the sensors are inputs to the control circuit. The control circuit evaluates the conditions (based on your logic thinking) and "outputs" switching of the pump.
Boncuk[/QUOTE
That was a good explanation, Thanks