The massive planets are the major obstacles to the solar wind. From auroral images in visible and ultraviolet light, but mainly from in situ measurements, scientists can infer the multiple interaction processes of the magnetized solar wind with the magnetospheres and ionospheres of the planets. The planets of our solar system have dynamo-generated magnetospheres or, as in the case of Venus or Mars, magnetospheres induced by ion currents, which have already been intensively studied by various space probes. This is one of the central topics of this chapter, which begins with a brief historical introduction. The functioning of the Earth’s dynamo, polarity reversals of the Earth’s magnetic field, electric radiation belts and current systems in the Earth’s magnetosphere, as well as the kinematics of charged particles trapped therein and their significance for near-Earth space weather are explained in detail.