The article provides an overview of localization, defined here as "translation specifically adapted to the local market and to the final user". Apart from the usual characteristics of any translation, localization adds its constrained nature, mainly in issues like space (translations have to fit in predetermined "boxes"), colors, icons, etc. Regarding the translators' profile, the main difference in this case is the need for a high command of IT, including specific translation tools like memories and machine-translation applications. The article also comments on internationalization, a counter-movement designed to save the expenses involved in localization, consisting of a tendency to produce culturally neutral IT applications which can be very easily and quickly translated. In a final instance, it discusses some computer tools, like memories and terminological applications which save a lot of time in the localization process. [Based on BITRA / J. Franco]