Information technology (IT) is widely understood to be the enabling technology of the 21st century. IT has transformed, and continues to transform, all aspects of our lives: commerce and finance, education, employment, energy, health care, manufacturing, government, national security, transportation, communications, entertainment, science, and engineering. IT and its impact on the U.S. economy-both directly (the IT sector itself) and indirectly (other sectors that are powered by advances in IT)--continue to grow in size and importance.