Postal history is the study of how mail has been sent and delivered throughout time. It includes the development of post offices, mail carriers, and postal systems in different countries. By examining old letters, stamps, and postal routes, historians can learn about communication methods and societal changes. The evolution of stamps is a key part of postal history. The first adhesive stamp, the Penny Black, was introduced in Great Britain in 1840, revolutionizing how people sent letters. Collecting and studying these stamps helps enthusiasts understand the cultural and historical significance of mail in various societies.