Tuning is pretty much the same as filtering.  The capacitors, inductors and resistors are chosen to give a desired output response for specific frequencies based upon the impedances.  For matching purposes, the impedance, “Z”, of the device is used to “match” that of the rest of the circuit, antenna or IC, to reduce line reflections or load mismatches as in transmission line theory.  An AC signal has low line losses if the impedance is uniform throughout the path.