Philately is the study of postage stamps and postal history. It also refers to the collection and appreciation of stamps and other philatelic products. While closely associated with stamp collecting and the study of postage, it is possible to be a philatelist without owning any stamps. For instance, the stamps being studied may be very rare or reside only in museums.

A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to customers who pay postage. Then the stamp is affixed to the face or address-side of any item of mail—an envelope or other postal cover —which they wish to send. The item is then processed by the postal system, where a postmark or cancellation mark—in modern usage indicating date and point of origin of mailing—is applied to the stamp and its left and right sides to prevent its reuse. Next the item is delivered to its addressee.