During conversational interactions such as tutoring, instruction-giving tasks, verbal negotiations, or just talking with friends, interlocutors’ behaviors experience a series of changes due to the characteristics of their counterpart and to the interaction itself. These changes are pervasively present in every social interaction, and most of them occur in the sounds and rhythms of our speech, which is known as acoustic-prosodic accommodation, or simply phonetic accommodation. The consequences, linguistic and social constraints, and underlying cognitive mechanisms of phonetic accommodation have been studied for at least 50 years, due to the importance of the phenomenon to several disciplines such as linguistics, psychology, and sociology. Based on the analysis and synthesis of the existing empirical research literature, in this paper we present a structured and comprehensive review of the qualities, functions, onto- and phylogenetic development, and modalities of phonetic accommodation.