Question

what is postcard and stamps

Answer 1

 postcard or post card is a rectangular piece of thick paper or thin cardboard intended for writing and mailing without an envelope. Shapes other than rectangular may also be used. There are novelty exceptions, such as wood postcards, made of thin wood, and copper postcards sold in the Copper Countryof the U.S. state of Michigan, and coconut"postcards" from tropical islands

Answer 2

a card for sending a message by post without an envelope, typically having a photograph or other illustration on one side is called postcard

a pattern or mark on (a surface, object, or document) using an engraved or inked block or die is a stamp