In the previous chapter, we have introduced the main features of abiogenesis, and we have quickly summarized the key properties that an entity must have, in order to be considered as a candidate “kind of living being”. In this second introductory chapter, we will briefly review the main concepts that will be called into play to come to a convincing account of OoL. These concepts (self-organization, collective self-replication and cell-like structures; see Sects. 2.2–2.4) will be treated in more detail in the following chapters, so we will limit here to briefly mention their role.