Kirchoff was a german scientist. He stated two laws. These laws are
Kirchoff's voltage law(KVL)
Kirchoff's current law(KCL)
An any closed circuit or mesh the algebric sum of emf's acting in that circuit or mesh is equal to the algebric sum of the products of the current and resistance of each part of the circuit.
The sum of the voltage rise is equal to the sum of voltage drop around a closed loop in a circuit
Current flow in circuits is produced when charge carriers travel though conductors. Current is defined as the rate at which this charge is carried through the circuit. A fundamental concept in physics is that charge will always be conserved. In the context of circuits this means that, since current is the rate of flow of charge, the current flowing into a point must be the same as current flowing out of that point.
It states that the sum of current directed into any node in a circuit is equal to the sum of the current coming out of the same node.