Meaning of impedance matching

imped'ance match"ing

Pronunciation: [key]
— Elect. Elect.
  1. the technique of choosing or adjusting electric circuits and components so that the impedance of the load is equal to the internal impedance of the power source, thereby optimizing the power transfer from source to load.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.