This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book presents the Swiss federal system at a glance and describes its origins which led to the current basic principles of Swiss federalism. It offers a predominantly "legal" view and deals with the constitutional requirements rather than empirical evidence. The chapter provides an overview, description, and analysis of the different subnational actors in Switzerland, namely at the regional and local level. It addresses the cantons' status in the Swiss federation, discusses the differences between national and cantonal political structures, and focuses, first and foremost, on the different branches of government within the cantonal political systems. The chapter also provides more attention to real politics and approaches the processes of Swiss federalism. Essentially, it shows how fiscal equalization and the allocation of tasks and between the Federation, the cantons, and the municipalities have developed over time.