In this chapter, the reader will familiarize themselves with a wide pallette of aircraft configurations, distinguished by location and main purpose of lifting surfaces. The chapter also presents the aircraft-related reference frames and introduces the concept of aircraft longitudinal static stability, as well as trim and balance, including how they can be measured and ensured by design. The reader will learn in detail how the pitching moment of the three basic aircraft aerodynamic configurations (wing-tail, canard, and tailless aircraft) can be estimated and what is meant by balancing an aircraft in flight. Aircraft stability is closely related to its aerodynamic center and the volume coefficients of the tail, and they are also thoroughly discussed in this chapter. In particular, the reader will find a series of crossplots intended to facilitate the correct sizing of the tail for the desired center of gravity envelope. Furthermore, the conditions for the minimum trim losses and a generalized drag polar for the three configurations of aircraft are presented. The chapter also discusses aircraft control, including the requirements imposed on the efficiency of control surfaces.