Fatigue is a typical phenomenon encountered during day-to-day usage of a product. This can however be avoided by designing a component against fatigue. This introductory seminar will explain the basic principles of fatigue versus strength, discuss on different failure modes and the influence of external factors - e.g. mean stress- on the fatigue properties of a component. On top, we will briefly discuss 2 main approaches to derive the fatigue life of a component.