It's termed a 'readymade'. A huge amount of discussion about the significance of readymade art has occurred in the past 100 years, but one theme has always been prominent and never fully resolved (not outside the artworld anyway).... what is an artist? Is an artist a person who makes art, a person who says they make art, a person who other people thinks makes art... a mixture of those, or something else entirely?
For Duchamp, this sort of thing was the end of the line, he turned to chess instead, but other artists have continued, and created numerous major and minor art styles since.
Obviously, this whole thing begs the question... what exactly is art?
