Order-sorted logic is a formal logical system that extends classical first-order logic by incorporating a hierarchy of sorts (types) for terms, structuring the domain of discourse. It is an academic concept and methodological approach focused on knowledge representation and logical inference within domains where entities exhibit inherent categorical structure and subtype relationships. Key characteristics include a sort signature defining a partially ordered set of sorts and strict type constraints on logical symbols, ensuring the type correctness of expressions. Its significance lies in enabling more precise and efficient modeling of structured domains, preventing type errors inherently, reducing the complexity of axioms compared to unsorted logic, and improving the tractability of automated reasoning systems in such contexts.