Airmail Stamp: Stamps issued specifically for air mail service.
Block: A set of four or more unseparated stamps still connected as they were on the original sheet.
Cancellation: A mark applied to a stamp to show it has been used and to prevent its reuse.
Definitive Stamps: Regularly issued stamps designed for everyday postal use, often available for extended periods.
First Day Cover (FDC): Envelopes bearing a stamp and a postmark from the first day that the stamp was issued.
Gum: The adhesive substance on the back of a stamp that allows it to adhere to surfaces.
Hinge: A small, gummed piece of paper used to attach stamps in an album, allowing them to be removed without damage.
Imperforate: Stamps without any separation perforations, often issued intentionally for collectors.
Mint: Describes a stamp in its original condition, as issued by the post office, with full gum and no postmark.
Perforation: The series of punched holes between stamps that facilitate easy separation.
Philately: The formal study and collection of stamps and postal history.
Plate Number: A unique number assigned to the metal printing plates used in the production of stamps.
Postmark: The official postal stamping on a letter or package that includes the date and place of mailing.
Souvenir Sheet: A commemorative issue of stamps, often printed on a small sheet with a decorative border, featuring one or several stamps.
Topical Collecting: The practice of collecting stamps by a particular theme or subject matter, such as animals, historical events, or famous figures.
Watermark: A deliberate thinning of paper during its manufacture that can be seen when held against the light, often used to deter counterfeiting.
Zeppelin Mail: Mail carried on airships, specifically Zeppelins, often bearing special stamps and postmarks commemorating the flights.