Embedded systems are often safety-critical applications where their correct operation is vital to ensure the safety of the public and environment. Examples include shut-down systems for nuclear power plants, fly-by-wire aircrafts, autonomous train control software or anti-lock braking systems in automobiles. Safety is a system property and thus cannot be studied by simply taking into account the software part of an embedded system, only. However, in this lecture we will address the general engineering aspects of safety in a rather superficial manner and mainly concentrate on the specific problems of safety-critical systems which contain (complex) software parts.