What is a hero? The American Heritage Dictionary defines the word as "a person noted for feats of courage or nobility of purpose, especially one who has risked or sacrificed his or her life."

The heroes you'll meet on these pages and in these films are different from those in the pages of most history books. They are not famous politicians or legendary soldiers — yet they have improved the lives of MILLIONS of people and made the world more secure. Their 'arsenals' are not of weaponry, but of creative ideas, dogged determination and a deep belief in their power to change the world. Also known as "social entrepreneurs," they develop innovations that bring life-changing tools and resources to people desperate for viable solutions.