This essay reflects on the philosophical postulates of the book "Los diccionarios. Introduction to the lexicography of Spanish" by the author Elena Bajo Pérez. This work is considered an introduction to the world of dictionaries and their relevance in the lexicography of the Spanish language. Throughout the text, different aspects related to lexicography, the evolution of dictionaries and their importance in the learning of Spanish will be examined, which is an essential introduction to the study of dictionaries and lexicography. In this book, the author establishes the theoretical and methodological bases necessary to understand the functioning and importance of dictionaries. The author begins by explaining that dictionaries are fundamental linguistic tools that allow us to access the knowledge and meaning of words. In addition to their consultation function, dictionaries also play a crucial role in language development, as they are a source of learning and guidance for speakers.