R is short for Radio, F is short for Frequency,so RF is for Radio Frequency. RF is a high-frequency electromagnetic wave which could input electromagnetic energy into dermal layers of the skin,stimulate the dermis,heat the collagen to 45~60 ℃, activate the collagen shrinking and re-generating, increase the thickness and density, so it could tighten and lift the loose skin, remove wrinkle and scar, make skin elastic and glossy.