What kinds of stamps are there?

There are several different types of stamps—for example, commemorative, definitive (sometimes called "regular" stamps), and special stamps. There are also several different formats for stamps, such as sheets, booklets, and coils. Stamps may be the conventional adhesive type ("lick-and-stick") or self-adhesive ("no-lick, peel-and-stick").

Definitive stamps are the most common. Generally small in size, they are printed in huge quantities (the same stamp is printed often in the billions), and often more than once. They often feature the head of an important person (such as a dead President) or some other symbol that is identified with the issuing country, like its coat of arms.

Commemorative stamps, are generally larger and more colorful than definitives, are printed in smaller quantities and are typically printed only once. They honor people, events, or subjects of importance to the issuing country's life and culture.

Special stamps—Christmas and Love, Holiday stamps (such as Christmas, New Years, Hanukkah, etc.), international rate, Priority Mail, Express Mail—usually are on sale for only a limited period of time.

Back of the Book stamps - airmail or air post stamps, semi-postal or charity stamps, postage dues, parcel post, registered mail stamps, revenue stamps and others. Called Back of the Book stamps or BOB stamps due to their typical location in most stamp albums.