This definition takes into account not only the laws of the States, but referred to the legal systems, but no reference to comparative law seeks to find the similarities and differences between different legal systems. To Arminjon, Nolde and Wolff comparative law collates and compares the rules and institutions of different legal systems in the world. This definition is a broader definition that refers to the comparison of the rules and institutions of various States without reference to the legislation, case law, enforceable and legal custom. For Julio Gonzales Ayasta comparative law is aimed at confronting the legal systems of various countries to determine what is common and differential between them and determine their causes. This definition refers to comparative law takes into account the main part of comparative law it is to find the similarities and differences between legal systems, and also aimed to determine the causes of such differences or similarities. To Guillerno Cabanellas comparative law is the branch of science general law whose purpose is the systematic review of positive law in force in different countries, and with the general character or any of its institutions, to establish similarities and differences. This definition refers to positive law, however, no comparative law study or compare only the positive law of different States, and the definition does not refer to the causes of the similarities and differences. For the record that this definition refers to comparative law as a field of law but it is necessary to clarify that comparative law is not a branch of right but is the application of the comparative method to the right.