How do parties differentiate themselves from each other, and how does this differentiation affect voters? This paper argues that alongside the more traditional party-system characteristics like the number of parties and the degree of ideological polarization, parties and party systems also vary through issue divergence, the degree to which there is conflict over what the key issues in politics ought to be. Using data from the Comparative Study of Electoral Systems, I demonstrate that voters perceive greater differences between parties when parties propose agendas that diverge with respect to issue emphasis. I then substantiate the practical relevance of these perceptions of party differences for voters by showing that respondents who perceive higher degrees of difference in their party system are likely to report higher levels of satisfaction with democracy and higher levels of electoral participation. These results contribute to our understanding of party systems and how they influence voter behavior.