This paper addressed the key aspects regarding large scale PV-PPs with frequency response capability and its applicability and pertinence in real power systems. First, we proposed a new terminology to denote the frequency support capability of inertia-less generation units during the first seconds after major power imbalances. We denoted this type of support as fast frequency response (FFR). Because no rotating parts following the swing equation are involved, we claimed that such capability in PV units cannot be classified as an inertial response