How does Hand Pump Work ?

Hand pump is used for bringing water from earth and is used almost every house in the world . But do you know how does hand pump work ? There are many reasons of hand pump's working . Since starting water
pump from ancient time , water pump is operated under the principle of  pressure theory . There are two plunger , one is top side and other is bottom side and which is sealed by valve. When with hand pressure , top plunger will rise above and take some water but bottom plunger which is sealed by tight valve , will not send it again to wall . So , water will reach outside and after this we can use this water 







Animated Picture shows the scientific system beyond hand pump working