Introducción a la Teoría de las Funciones Lexicográficas is the first monographic volume in Spanish that offers a general approach to the foundations of the Function Theory of Lexicography, which aims to guide lexicographic work based on three central aspects: data, user needs and access routes. In a context of change and reinvention, the aim of this book is to introduce lexicographers, researchers, students and anyone interested in learning lexicography to one of the most revolutionary theories on the international lexicographic scene. Lexicographic functions have come to conceive and classify new lexicographic products from a different perspective. The theory is based on a pragmatic vision of lexicography that allows the creation of new tools whose limits are set only by the users and their functional and consultation needs.