​The International Standard Industrial Classification of All Economic Activities (ISIC) is the international reference classification of productive activities. Its main purpose is to provide a set of activity categories that can be utilized for the collection and reporting of statistics according to such activities. Since the adoption of the original version of ISIC in 1948, the majority of countries around the world have used ISIC as their national activity classification or have developed national classifications derived from ISIC. ISIC has therefore provided guidance to countries in developing national activity classifications and has become an important tool for comparing statistical data on economic activities at the international level. Wide use has been made of ISIC, both nationally and internationally, in classifying data according to kind of economic activity in the fields of economic and social statistics, such as for statistics on national accounts, demography of enterprises, employment and others. In addition, ISIC is increasingly used for non-statistical purposes. This fourth revision of ISIC (ISIC, Rev.4) is the outcome of a review process that spanned several years and involved contributions from many classifications experts and users around the world. This process resulted in an ISIC structure that is more detailed than the previous version, responding to the need to identify many new industries separately. This is especially applicable in the case of services. Moreover, the relevance of the Classification has been enhanced with the introduction of new high-level categories to better reflect current economic phenomena. A new section entitled “Information and communication” (see part three, sect. J) is one such innovation. Comparability has also been enhanced with a number of other regional activity classifications, thus making this version of ISIC a much improved tool for international data comparison. A number of alternate aggregations have been included in the present publication. They provide analytical tools for areas which, for conceptual reasons, do not lend themselves to aggregation within the existing ISIC structure. Among the alternate aggregations included in this version of ISIC are aggregations for information and communications technology, the informal sector and non-profit institutions, as well as two aggregations for national accounts-type analysis, one at very aggregated and another at an intermediate level of ISIC. The structure of the fourth revision of ISIC was considered and approved by the Statistical Commission at its thirty-seventh session, in March 2006,1 as the internationally accepted standard. It now replaces the third revision of the classification2 and its update, Revision 3.1,3 which have been in use since 1989 and 2002, respectively

​La CLASIFICACIÓN INDUSTRIAL INTERNACIONAL UNIFORME DE TODAS LAS ACTIVIDADES ECONÓMICAS (CIIU) es la clasificación internacional de referencia de las actividades económicas productivas. Su principal finalidad es facilitar un conjunto de categorías de actividad que pueda utilizarse para la elaboración de estadísticas por actividades. Desde la aprobación de la versión original de la CIIU en 1948, la mayoría de los países del mundo han utilizado la CIIU o elaborado clasificaciones nacionales derivadas de ella. Por consiguiente, la CIIU ha proporcionado orientación a los países para elaborar las clasificaciones nacionales de actividades y se ha convertido en una herramienta importante para la comparación de datos estadísticos sobre actividades económicas a escala internacional. En su 33º período de sesiones, celebrado en marzo de 20021 , la Comisión de Estadística examinó y acogió con beneplácito el proyecto final de la revisión 3.1 de la CIIU, que sustituye ahora a la tercera revisión de la clasificación2 , que se venía utilizando desde 1989.