Conceptions of party family serve as signals to political actors, but also as analytical categories for scholars to classify parties with the purpose of developing theoretical arguments about their origins, electoral and executive government trajectory, and policy impact. Historically, political “brands” and scholars’ efforts to distinguish party “families” originate in the mobilization of mass parties following the introduction of universal suffrage and pinnacle in the literature on political cleavage formation. For contemporary research, party families may be classified by at least three analytical dimensions indicating principles according to which they generate policy positions on questions of economic distribution (greed), political and social governance (grid), and delineation of polity membership status (group). The configuration of positions on the three dimensions constitutes a party’s ideology, which may be grouped into a party family. In any particular polity, only a subset of the conceivable ideological positions is empirically present. Moreover, there are parties that change their party family affiliation over time, if not their brand names. Finally, many party classifications do not meet the criteria of party family as introduced here. This applies to the characterization of parties according to whether they are based on personalism, clientelism, cartel formation, catch-all politics, or niche strategy.