Kirchhoff came up with two laws. They pretty much say the same thing: Everything going out is matched by everything coming in. No exceptions.

• Kirchhoff’s Voltage law (KVL): The total of voltages leaving a node must be matched by the total of voltages entering the node.
• Kirchhoff’s Current law (KCL): The total of currents leaving a node must be matched by the total of currents entering the node.