Political parties are key actors in democratic systems. Parties not only shape electoral competition in democracies, but also structure issues for voters. Moreover, parties are quite diverse and represent different political ideologies. This course focuses on parties as crucial actors in political systems, for elections and in parliament. First, we start with important concepts of political science necessary to explore parties in more detail. Second, we focus on different types of parties, their issues, and their voters. Third, we examine intra-party behavior, including party elite candidate selections and elite behavior in parliaments.