A non-negligible number of individuals and companies active in various sectors derive their income from International sports events (ISEs), and such income, along with the economic transactions, raise stimulating income tax and Value-added tax (VAT) issues. This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book describes the key concepts and the main actors of ISEs. It examines the concepts of ‘sport’ (and respectively ‘eSports’) and ‘sports event’, the bidding procedure and the main actors in charge of organising ISEs, as well as the unequal distribution of income within the sports sector. The book describes the key tax law concepts and mechanisms that are frequently referred to throughout the analysis. It identifies income that may derive from ISEs and eSports tournaments, as well as examines the taxation modalities of the income sources (income tax) and transactions (VAT) concerned.