This book is intended for those who are taking the first steps in the knowledge of canon law and, above all, to those who are starting to specialize in it through study and research. This book covers two subject groups: the first subject is the law of the People of God or the juridical dimension of the Church, and the second, gnoseology and methodology. The first one answers the question, « What is canon law and what are its basic features? » while the other answers the question, « How can we know and interpret that law? » They are the two major subjects faced by the student of canon law. This book seeks to answer them in a synthetic style.