In this paper, key aspects of electoral systems were investigated, analyzing their theoretical foundations, practical implications and influence on political processes in democratic societies. The paper draws on a wide range of theoretical frameworks and concepts to provide a comprehensive overview of the topic. In the theoretical framework of electoral systems, the basic concepts and definitions related to electoral systems are considered, investigating issues of representativeness and proportionality. Also, the difference between majoritarian and proportional electoral systems is analyzed, including combined and specific variations. The paper also deals with the impact of electoral systems on political pluralism and investigates criticisms and controversies related to the theoretical basis of electoral systems. Through the analysis of the connection between electoral systems and political behavior, the historical development of electoral systems and how they shaped political behavior over time was investigated. The importance and role of political systems are analyzed, where key aspects of the importance of electoral systems in democratic societies are explained, including democratic legitimacy, stability of political institutions, formation of political pluralism, prevention of concentration of power, encouragement of political participation and creation of extremism and polarization. The most important part deals with the criteria and indicators of the success of electoral systems. Different criteria and indicators used to evaluate the success of electoral systems were studied. Issues of electoral participation, number of political parties, electoral volatility, measurement of proportionality, party power (for example, Shapley-Shubik index, Banzhaf index) and coalition, and stability of government as important components of electoral systems are investigated. This thesis provides a comprehensive overview of key aspects of electoral systems and their impact on political processes.