The electrophiliciy index proposed by Parr, Szentpaly, and Liu provides insight into almost every arena of chemistry and encompases information about the structure, properties, stability, reactivity, interactions, bonding, toxicity, and dynamics of many electron systems in ground and excited electronic states. The whole gamut of the conceptual density functional theory lends support toward the electrophilicity index and helps it realize its full potential. As is the case for most of the conceptual DFT-based reactivity/selectivity descriptors, the global and local electrophilicities possess strong interpretive power.