What is KCL and KVL

KCL is Kirchoff Current Law, this law says the total current walk pass a node is always zero, it is just like a water supply system, if the whole apartment is considered as a node, the water that flow outside of the apartment, no matter it is consumed, flushed down the toilet etc, is equal to the water that is injected to the apartment by the water system.

KVL is Kirchoff Voltage Law, and KVL says the total voltage difference of a closed loop is zero, imagine the water flowing from the top of the mountain, down to the valley and then travel through the undergroun water system back to the top of the montain, total water potential energy differnce is zero.