Twenty-five years after the publication of a groundbreaking text that first provided a comprehensive overview of contemporary Italian and its varieties from a sociolinguistic perspective, an updated revision appears. This new edition reflects the significant increase in knowledge in this field over the past quarter century. The structure and complete textual material of the original edition have been retained, with some errors and marginal details removed and individual formulations improved. Each chapter has been given a new subchapter focusing on substantive and bibliographical updates of the main topics.