News photographs should tell a story, or part of a story, by capturing some sort of action or activity. Taking a photograph of a house occupied by someone who has been in the news is unlikely to be of interest to a news editor. However an image of the same property, seen as a background while the occupier confronts protesters at the gate, might generate a lot more interest. The story is whatever is going regarding the property to cause problems between the occupier and the protesters - not the property itself.
Good news photographers or photojournalists therefore combine the skill of telling a story with the art of photography. They do their best to tell the whole story, or the whole of a particular element of a story. They also strive to do so in a complete and honest manner - at least that is how it should be done. In practice, many photojournalists have experience in both areas, telling a story and composing good images, although the digital age has reportedly encouraged more print reporters to accept photographic assignments - resulting in evidence of lower photographic standards..
News photographers are themselves also the source of many stories. They live much of their working lives out in the community that they serve, and are likely to be among the first to find developing stories. Life goes on all the time, evolving as it does so. Stories and photographs are everywhere, even when nothing unusual appears to be happening. The challenge for a photojournalist is to find aspects of ordinary life that can be made interesting, and then do it.