Heidegger's fundamental work is one of the most important in the history of philosophy. It has been translated into many languages of the world and has acquired thousands of interpretations. First published in 1927 in the Yearbook of Philosophy and Phenomenological Research, dedicated to Husserl. Resuming the primordial philosophical questioning about being, about the meaning of being, Heidegger makes a revolution in the understanding of ontological issues, revealing traditional prejudices and revealing the deep connection between time and being. According to Heidegger, being itself is time and only becomes intelligible in the horizon of time. Heidegger's approach to being is mediated by the analytics of the being that we are (Dasein - presence, here-being), since it is in the being of this being that things happen.