The article discusses the application of conceptual Density Functional Theory (DFT) indices to the study of organic reactivity. It covers global and local indices such as electronic chemical potential (μ), electrophilicity (ω), nucleophilicity (N), Fukui functions (f(r)), Parr functions (P(r)), and the local reactivity difference index (R_k). These indices are derived from the electron density and its derivatives, providing insights into the reactivity of organic molecules. The authors highlight the importance of these indices in understanding the mechanisms of polar reactions, particularly those involving C-C bond formation through the coupling of pseudoradical centers. The article also compares different indices, such as the nucleophilicity N and N' indices, and discusses their predictive capabilities for the reactivity of organic molecules. Additionally, it introduces the Parr functions, which are useful for characterizing the most electrophilic and nucleophilic centers within a molecule, and the local reactivity difference index (R_k) for predicting local reactivity within a molecule. The article concludes with a discussion on the application of these indices to free radicals, including the global and local indices for free radicals and their role in explaining regio- and chemoselectivity in radical reactions.The article discusses the application of conceptual Density Functional Theory (DFT) indices to the study of organic reactivity. It covers global and local indices such as electronic chemical potential (μ), electrophilicity (ω), nucleophilicity (N), Fukui functions (f(r)), Parr functions (P(r)), and the local reactivity difference index (R_k). These indices are derived from the electron density and its derivatives, providing insights into the reactivity of organic molecules. The authors highlight the importance of these indices in understanding the mechanisms of polar reactions, particularly those involving C-C bond formation through the coupling of pseudoradical centers. The article also compares different indices, such as the nucleophilicity N and N' indices, and discusses their predictive capabilities for the reactivity of organic molecules. Additionally, it introduces the Parr functions, which are useful for characterizing the most electrophilic and nucleophilic centers within a molecule, and the local reactivity difference index (R_k) for predicting local reactivity within a molecule. The article concludes with a discussion on the application of these indices to free radicals, including the global and local indices for free radicals and their role in explaining regio- and chemoselectivity in radical reactions.