Ils servent a obtenir des informations (ou donnees) pour le systeme informatique tel que clavier (frappe de texte), souris (pointage), scanner (numerisation de documents papier), micro, webcam, etc.

Exemples :

                                                                                 

                                                                              

                                                                                                                                     Clavier

                                                                       

                                                                                                                                      Souris

                                                                             

                                                                                                                                     Webcam