Besides research, education is the raison d’être of each university. Education can help close equity gaps and maintain social cohesion between and within countries. In this context, the digitisation era offers new opportunities, for example, in the form of distance and online learning. However, innovations can also come with challenges, such as employed and unemployed people requiring to adapt to a progressing working environment at ever shorter intervals (life-long learning). Consequently, it is increasingly important to gain free access to up-to-date educational materials about a wide range of subjects and at multiple academic levels. In this document, we introduce the concept of Open Educational Resources (OER). We start with establishing a definition of OER, what is needed to call educational materials OER, and the differences in comparison to related concepts, such as Massive open online courses. We then address the question of who can benefit from OER. It reports on the incentives to publish OER taking into account the perspectives of the involved stakeholders, i.e., the general public, universities and lecturers, and students. Afterwards, we pay attention to the challenges that come with OER. Subsequently, we provide a list of potential business models around OER, their underlying concepts, benefits, limitations, and projects making use of them. We also consider the paradox that OER are not intended to generate revenue but that ignoring income can make OER unsustainable. The document concludes by outlining possible steps to realize OER (e.g., organizing a round table to initiate a discussion about how to realise OER at the faculty level).