A postage stamp is a special postage mark issued and sold by national (and other) postal offices and has a certain nominal value. Serves to facilitate charges for postage of items (items) carried out by mail. Typically, a stamp is a small piece of paper, predominantly rectangular in shape, usually with serrations and glue on the back. In addition to the face value, stamps may indicate the name of the postal administration that issued them; often it depicts various symbols, decorative elements and drawings. Postage stamps are collectible.