This chapter does not deliver an exhaustive treatment on automotive electronics. There are other books on this topic (e.g. [21, in German] or [65]). It will show which kind of electronic systems can be found in present and near-future cars, classify these systems from an electromagnetic compatibility (EMC) perspective into functional domains and show their properties concerning EMC and functional safety. In particular, it shows how electronic control units, power supply, communication and connections to sensors and actors work. This chapter is also a good frame for a short introduction to drive-by-wire technologies, the communication of the car with other cars (Car2Car, Car2C), the road side infrastructure (Car2I) or both (Car2X) and for autonomous driving.