Political issues are relevant for everybody, but they are often complex and difficult to understand. Political Science provides theories and instruments to analyze these matters and it is useful to have at least a basic knowledge of this subject. This book is intended to give a short and easy-to-read introduction to Political Science and is based on introductory courses at the University of Osnabr ck in Northern Germany. The most important theories and debates are presented and a short overview on recent developments is given. Topics are e.g. policy analysis, the motives for policy making, theory of government and governance, international relations, energy and security policy. This book should not replace teaching books and the work with scientific literature, but may motivate the reader to learn more about this fascinating subject.