Gustav Robert Kirchhoff
(12 March 1824 – 17 October 1887) was a German physicist who contributed to the fundamental understanding of
electrical circuits, spectroscopy, and the emission of blackbody radiation by heated objects. He coined the term
"black body" radiation in 1862, and two sets of independent concepts in both circuit theory and thermal emission
are named "Kirchhoff's laws" after him.
 Wikipedia
The fundamental concepts of Kirchhoff's Current Law and Kirchhoff's Voltage Law are illustrated
below. Both assume a totally contained system where energy is conserved.
The current flowing into a node or branching point is equal to the sum of the individual currents leaving
the node or branching point.

The algebraic sum of all the voltages around any closed path in a circuit equals zero.
