This is an introduction to the study of political parties and party systems. It focuses primarily on liberal deocracies and the approach is a comparative one. The book's aim is to explain to students of politics how and why parties and party systems differ from one country to another. However, it also seeks to provide a more detailed understanding of party politics in five particular countries. Most of the chapters are divided into two sections. In the first section general themes and arguments about a topic are introduced, and examples from a large number of countries are discussed in relation to it. In the second section, particular attention is paid to five of the largest liberal democracies - Britain, France, Germany, Japan, and the United States.