a movement that sprung from the 1950s as a statement against the traditional art of the time. It focused on the thought that popular culture was as good as any fine art, so ads and commercials were admitted into museums for the first time. Whatever spoke of celebrities, mass production and consumption was worthy of a frame and an exhibition in a museum. This is when the entire world became an art gallery and poor people didn't need to pay to see a show anymore.
The actual pop artworks focus on the machine: repetition, reproduction, and easy do-it-yourself art activities. It emphasizes the printing techniques by enlarging the printing dots or using photocopies or simple cutting and pasting from magazines.
See for example: Jasper Johns, Andy Warhol, Robert Rauschenberg, Roy Lichtenstein, Richard Hamilton.