This work is about clearly illustrating the working principle of flux switching machines. In the past, different topologies regarding stator-/rotor configurations were presented and evaluated. Moreover, optimization of the operational characteristics was considered. The focus was on optimizing the shape of utilized components. However, the principle of torque generation is not clear at first sight, as typically the number of poles of the magnetic field due to the permanent magnets and due to the winding arrangement are not of same number. The reason for generating a net torque considering an entire period is the flux modulation due to the rotor teeth. A thorough explanation is presented featuring both, theoretical aspects as well as numerical studies utilizing finite element simulations. Results can help to derive general understanding of the working principle and will facilitate the development of new configurations.