Photojournalism
Photography made to report news, bound by professional standards of accuracy and non-interference.
In depth
The defining constraint is that the photographer may not alter what happened, before the shutter or after it: no directing, no adding or removing elements, no misleading captioning. Permitted processing is limited to what a darkroom could do to a whole frame — exposure, contrast, colour balance, cropping — and even cropping is contested.
Examples in practice
A news agency dismisses a photographer for cloning out a distracting object, regardless of the picture's quality.