= Resonance =

Resonance is the phenomenon in which the impedance from several
capacitors/inductors cancel each other out in a circut. This cause the circut
to be "tuned" to a certain frequency. Resonance creates a filter, rejecting
certain frequencies and allowing others.

Each capactiors and inductors create some reactance, and cause either voltage
or current to lead/drag behind the other. When a circut is resonant, both line
up again at the end of the circuit, leading the inductors and capacitors to
appear as a short circuit.