Technology has existed for as long as humankind has invented items that improve and enhance daily living. The innovators of technology profiled in this comprehensive resource have affected nearly every facet of life, from transportation and communication to science and entertainment. Their developments have built upon one another, each a stepping-stone toward even greater advances in technology. Their names range from the familiar—such as Thomas Edison—to the more obscure—such as Henrietta Swan Leavitt—but their contributions to today's world are all vital.