Metal or Plastic nail for fastening two or more pieces together. It has a head at one end and a base at the other end, in the male/female version. In cheaper versions there is only a head that opens in the form of a star to block the rivet in the material.  A rivet can also be used to attach hooks on the upper. Sometimes a rivet is used only as a decoration.

Translations

Dutch: 
Klinknagel
French: 
Rivet
German: 
Niete
Italian: 
Ribattino, Rivetto
Portugese: 
Rebite
Spanish: 
Remache