In this article, models and functional levels of information technology (IT) has been concerned by studying its concept and features, and recently it has been considered as one of the production sources in the efficacy function and its role has been examined in the economic performance of institutions, countries and other industries. Today, the significance and necessity of information systems is understood, since most organizations need such systems for their success. Its purposes include: decrease of costs, competitive intelligence, and quick response to the environment and competitors we are dealing with.