The plastics industry is an important part of the European and global economy. Beyond the traditional definition of the plastics industry with the three domains of plastics production, plastics conversion, and plastics machinery, there are important other areas belonging to the plastics ecosystem namely recyclers, service providers, science, associations, trade fairs and many others. All participating institutions work closely together in complex, mostly international networks, often within the framework of customer–supplier relationships that have been built up and proven over decades. The necessary transformation of today's linear production system is dominated by linear supply chains to a circular economy, with its demanding requirements, deeply intervenes in these structures and workflows. The phasing out of fossil raw materials while waste is becoming an important feedstock resource is not only changing the world in plastics production but also in all other areas of the plastics ecosystem. To assess the impact of this change on established processes and companies, it is necessary to understand the structures existing today. In this chapter, the sectors and sub-sectors are presented in detail. In doing so, the essential characteristics of each sector are dealt with in a structured manner, the important actors are named, and their roles are described. Regional aspects and key figures complete the picture.