The chapter introduces the concept of outranking relations, which emerged from practical challenges in decision-making processes. It highlights the numerous applications of this concept in various fields, including recent studies by researchers such as Barda et al., Clímaco et al., Martel and Nadeau, and others. The paper is divided into several parts: the first part describes the real-world problems for which the outranking approach is suitable and presents the concept of outranking relations; the second part delves into the basic ideas and concepts used to build these relations; the third part defines outranking relations for the main ELECTRE methods; and the final part discusses practical considerations. In the introduction, the author specifies the initial elements required for understanding the outranking approach: 1. A set \( A \) of potential actions (alternatives) that can be implemented jointly. 2. A consistent family \( F \) of \( n \) criteria \( g_j \) that reflect the perspectives of decision-makers. 3. The performance of an action \( a \) under each criterion \( g_j \), denoted as \( g_j(a) \), which can be a real number or a qualitative assessment. 4. The relationship between performances, where \( g_j(a') \geq g_j(a) \) implies that \( a' \) is at least as good as \( a \) from the perspective of the \( j \)-th criterion. 5. The possibility of imprecision, uncertainty, or inaccurate determination of performances, leading to judgments of indifference or strict preference based on the \( k \)-th criterion.The chapter introduces the concept of outranking relations, which emerged from practical challenges in decision-making processes. It highlights the numerous applications of this concept in various fields, including recent studies by researchers such as Barda et al., Clímaco et al., Martel and Nadeau, and others. The paper is divided into several parts: the first part describes the real-world problems for which the outranking approach is suitable and presents the concept of outranking relations; the second part delves into the basic ideas and concepts used to build these relations; the third part defines outranking relations for the main ELECTRE methods; and the final part discusses practical considerations. In the introduction, the author specifies the initial elements required for understanding the outranking approach: 1. A set \( A \) of potential actions (alternatives) that can be implemented jointly. 2. A consistent family \( F \) of \( n \) criteria \( g_j \) that reflect the perspectives of decision-makers. 3. The performance of an action \( a \) under each criterion \( g_j \), denoted as \( g_j(a) \), which can be a real number or a qualitative assessment. 4. The relationship between performances, where \( g_j(a') \geq g_j(a) \) implies that \( a' \) is at least as good as \( a \) from the perspective of the \( j \)-th criterion. 5. The possibility of imprecision, uncertainty, or inaccurate determination of performances, leading to judgments of indifference or strict preference based on the \( k \)-th criterion.