Documentary photographs tell stories with images. The main difference between photojournalism and documentary photography is that documentary photography is meant to serve as a historical document of a political or social era while photojournalism documents a particular scene or instance.
A documentary photographer may shoot a series of images of the inner city homeless or chronicle the events of international combat. Any topic may be the subject of documentary photography. As with photojournalism, documentary photography seeks to show the truth without manipulating the image.