Pop art is an art movement that emerged in the mid-1950s in Britain and in the late 1950s in the United States. Pop art presented a challenge to traditions of fine art by including imagery from popular culture such as advertising, news, etc. In pop art, material is sometimes visually removed from its known context, isolated, or combined with unrelated material.
http://www.photoshoptutorials.ws/photoshop-tutorials/photo-effects/pop-art/