The word "code" has several different meanings. Dr. Judy Walker discusses several types of codes and how they have affected daily life throughout history and today. When information is transmitted, errors are likely to occur. This problem has become increasingly important as tremendous amounts of information are transferred electronically every day. Coding theory examines efficient ways of packaging data so that these errors can be detected, or even corrected. Walker presents the material in a conversational tone. No previous experience in coding theory or algebraic geometry is required.