Preference aggregation is the process of combining individual preferences or opinions to reach a collective decision. This method is commonly used in various fields, such as economics, political science, and social choice theory, to understand how groups can make decisions that reflect the desires of their members. Different techniques, like voting systems or ranking methods, are employed to aggregate preferences. For example, the Borda count and Condorcet method are popular voting systems that help determine a group's overall preference by considering the rankings provided by each individual.