The conceptual apparatus in public administration sets up along with the development of the Executive Power itself. The goal of the article is to provide wide readership with currently used notions which reveal the implication of most institutes, instruments and mechanisms of the Executive Power. Many of these notions have become sustainable and do not cause experts’ debates; they are commonly used now. Some notions have been borrowed from foreign experience and adapted to Russian native realities; others have emerged from Russian practice of reforming public administration that offered new efficient institutes and instruments of regulation. The most important notions and categories have been defined legislatively. But, legislative provisions do not always clearly reveal functional peculiarities of these or other mechanisms of public administration. The authors of the article precise some implicit points of the notions and definitions, mainly the interpretation of public service and its quality.