Abstract
This chapter, devoted to the theoretical framework of internationalization strategy, intends to perform a reflection on its main theories and studies. The authors discuss the main motivations that firms face to internationalize their activity as well as the aspects related to the success of approaching new markets. Then it also characterizes the main risks associated with the decision of internationalization and international trade. The authors will also present developed tools to support the two starting decisions that companies face in this type of projects: where and how to internationalize. They also intend to go into the decision of direct investment in international markets, providing knowledge about different perspectives, as several empirical studies show a more detailed vision of this strategic option and its main financial impacts on business. Finally, it discusses the main conclusions about the relation between internationalization and the performance of companies.