Welcome to GrayHair's Postal Glossary. This web-based tool is designed to provide detailed, easy-to-understand definitions for anyone interested in learning more about terms currently being used in the postal industry. Along with definitions, this glossary provides video clips and diagrams where possible to further enhance your learning experience. Whether you are a postal employee, mailer, service provider or someone trying to better understand the complicated industry vernacular, our Glossary can help by explaining the subtle difference in today's complicated postal terms.